Crop Management - Science topic

Common intercrops with solanaceous crops in natural farming include legumes (like beans and peas), leafy greens (such as spinach and lettuce), root vegetables (like carrots and radishes), and aromatic herbs (such as basil and cilantro) to enhance soil health, reduce pests, and increase biodiversity.

AI has significant potential to optimize farming practices, improve crop management, and address various agricultural challenges. Here’s how AI can be applied in these areas, along with considerations of ethical and practical implications:

### Optimizing Farming Practices

1. **Precision Agriculture:**

- **Data Collection:** AI can analyze data from sensors, drones, and satellites to provide real-time insights on soil conditions, crop health, and weather patterns.

- **Yield Prediction:** Machine learning models predict crop yields based on historical data and current conditions, helping farmers make informed decisions.

2. **Automated Machinery:**

- **Robotics:** AI-driven robots can automate tasks such as planting, weeding, and harvesting, reducing the need for manual labor and increasing efficiency.

- **Tractors and Drones:** AI enhances the capabilities of autonomous tractors and drones for precision planting, spraying, and monitoring.

3. **Resource Optimization:**

- **Irrigation Management:** AI systems optimize water usage by analyzing weather forecasts, soil moisture levels, and crop requirements, leading to more efficient irrigation practices.

- **Fertilizer Application:** AI algorithms determine the precise amount and timing of fertilizer application, minimizing waste and environmental impact.

### Improving Crop Management

1. **Disease and Pest Detection:**

- **Image Analysis:** AI-powered image recognition systems can detect diseases and pests early by analyzing images from drones or cameras, allowing for targeted treatment.

2. **Soil Health Monitoring:**

- **Predictive Analytics:** AI models predict soil nutrient levels and recommend appropriate amendments to maintain soil health and enhance crop productivity.

3. **Crop Breeding:**

- **Genetic Algorithms:** AI helps in identifying desirable traits in crops and accelerating the breeding process through genetic analysis and simulation.

### Addressing Challenges in Agriculture

1. **Climate Change Adaptation:**

- **Forecasting:** AI models predict climate change impacts on agriculture, helping farmers adapt by recommending suitable crops and practices for changing conditions.

2. **Resource Scarcity:**

- **Efficiency Improvement:** AI optimizes resource usage, reducing the strain on water and soil resources and minimizing the environmental footprint of farming.

### Ethical and Practical Implications

1. **Sustainability:**

- **Positive Impact:** AI can contribute to sustainable farming by optimizing resource use and reducing waste, which supports environmental conservation.

- **Potential Concerns:** Over-reliance on AI may lead to loss of traditional farming knowledge and practices. Ensuring that AI solutions are designed with sustainability in mind is crucial.

2. **Resource Management:**

- **Enhanced Efficiency:** AI enables more precise resource management, but it also requires significant infrastructure investments and technical expertise, which may not be accessible to all farmers.

3. **Automation Risks:**

- **Job Displacement:** Automation in agriculture may lead to job loss for farm workers. Balancing technology adoption with workforce development is essential to mitigate this impact.

- **Data Privacy:** AI systems collect and analyze large amounts of data. Ensuring data privacy and security is vital to protect farmers' information.

4. **Equity and Access:**

- **Technology Gap:** There is a risk that small-scale and resource-limited farmers may not benefit equally from AI advancements. Efforts should be made to ensure equitable access to AI technologies and support for all farmers.

Integrating AI into agriculture offers numerous benefits but requires careful consideration of its broader implications to ensure that it contributes positively to the farming industry while addressing potential risks and ethical concerns.

Peter Raeth Thank you.

In precision agriculture, geodesy establishes accurate spatial reference, while GIS combines and analyzes diverse spatial data layers for informed decision-making. Geodesy ensures precision in location, while GIS enhances the understanding of spatial relationships critical for effective crop management. Together, they contribute to optimizing resource use, increasing efficiency, and improving overall agricultural productivity.

Good question!

Better to do your research knowledge gaps among farmers, social groups, gender, age groups for different crop management! How is the knowledge transfer over generation? What is the interest of different social groups? What is the limiting factor for technology use for the different members of the society mentioned above? These are only few of the research questions? You many also deeply and carefully look at , at what stage of the research should farmers participate for the selection of any crop variety?

please read my paper in MAYDICA (foliar Ti for corn)

I think you should increase offline interaction with a variety of groups and clubs in the field you want to research or develop

interested

Othman Muayad Mohammed Tofeq

check this link maybe help you

https://homeguides.sfgate.com/grow-maize-greenhouse-23237.html

see link below ↓↓↓

One of the most important stages of corn growth is the knee high stage. The pH must be examined, salinity, and disease incidence

see link below ↓↓↓↓

Luz G. Asio

Saleh Aljubouri

Hadeel Alsarraje

Soil quality is measured by physical, chemical and biological indicators. Soil biological properties like microbial biomass carbon, microbial biomass nitrogen, soil respiration, mineralizable nitrogen and sulphur, soil microorganisms, etc. are import soil health indicators. Biological diversity is also considered in soil quality index computation.

Although we are getting through lockdown and all industrial works get hampered but on case of agriculture up to production we have no problem in case of organic farming as all things available in local area this also an oppertunity to learn some new lesson for new start up with independency on chemical fertilizer and many more but in case of market and supply the transport of agricultural goods is some what free to so safely we can calloberate and work easily with some new dimension in agriculture too..

Over watering is the main issue in papaya trees. We have practical experience at our farm on variety Red lady. Papaya should be planted on raised bed. Irrigation should be restricted to furrows only. The water should not touch the plant in any condition. This crop is very sensitive to water logging.

Dr. Manoj, You have mentioned all latest applications related to precision agriculture. Yes, You can do the same. There will be use of Bigdata, and ML. Further, research can be done in confined area with IoT to develop accurate figures related to variables under consideration. Very less practical work has been done in this aspect. But enough literature is there on the basis of theoretical concepts.

since about one half of the total cereal grain carbon foot print is for supplemental nitrogen the use of legumes is highly recommended. The use of legumes and the organic amendment of manures and composts can eliminate any requirement for supplemental nitrogen.

Besides carbon footprint the ability to get carbon sequestration from the agricultural system can be critical. In the monsoon environment of India the efficiency of water usage is dependent of the soil organic matter which has largely been depleted in may subcontinent areas. One of the best ways to increasing both soil organic matter and the ability to have high crop production is the integration of the plant and animal systems. When winter small grain can be used to establish a permanent mixed forage this stimulates a grassland type of environment which maximizes soil improvement.

Beside the establishment of legume foundation and mixed agricultural system the efficiency of the system depend on getting the high soil pH and balancing the soil nutrition through addressing deficiencies and toxicities.

By focusing on the biological input in the soil the requirements for agrichemical inputs and their issues can be avoided. The use of tillage practices can aid by using no till methods and substituting biological controls for the agrichemical.s

The system approach starts with a baselining of the soil conditions the use of soil analysis which leads to soil conservation and remediation plan.

The periodic assay of the soil and plant analyses serves as a way of monitoring and indicating when adjustments are needed.

This type of approach would ideally utilize teams of farmers and scientists who can interact together in the goals which would be applied in generalized regional approaches to extend the benefits from the approach and use the input efficiently.

Practices of production can be quantified for their carbon footprint and the results on the soil are used to determine sequestration as ongoing evaluation and adaptation.

Sorry

There are various crop models that can do this. Both DSSAT and APSIM have a soybean module and capacity to simulate a changing climate. There are also other modelling options that you could explore, but both DSSAT and APSIM are free and quite capable.

Thanks! Maybe I didn't explain enough! I have more families, but majority of genera or species are from those 2! But even if they are in the same taxon they have biochemical and genetics differences! Example: I have 3 clusters using DNA sequences from Enterobacter spp group and one group shows a higher production of AIA! It appear even in the tree with all sequences from this study plus refrence strains, but I don't know if it will be judged accurate enough for publication using one group/family as an outgroup for the others! Or I'll have to build a separate tree with an outgroup for each Genera!

That's a tricky question. Actually integrated pest management is the tactics to control the pest population by means of some combined control program (Cultural, chemical, mechanical, botanical etc); while integrated crop management is the practice of culture different crops at a same time in a same field to enhance the crop yield dramatically.

My guess is that it is a cutworm of some sort: the larval stage of a moth in the Noctuidae (it might be some other caterpillar, but cutworm is a very common situation). The mosquito netting suggested by Kulvir is an excellent idea. Insecticides could be used, but they might affect your experimental results. The netting will reduce sunlight. Usually it is not enough to cause problems, but that depends a great deal on your research question. You can get fancier, make a cage with netting on all sides and a clear plastic roof. Be careful about the ground. cutworms hide in cracks in the soil, and are experts at finding or making a hole in your netting. They also hide in the soil in pots. It might help to build a table. The legs of the table can be put into small cans of oil or talc powder or soap. Alternatively put something like tanglefoot on the legs. Then the cage can go on the table, and the new plants in the cage. If you use old plants, you might be bringing the pest with you.

Since this is under controlled condition and your temperature setting is 33-deg C, it might be heat injury (whitish blotch on young emerging leaf) and not nutrional disorder since  the older leaves look green and healthy. What's  the reason for setting temperature at 33-degrees? Are you studying response of plant to high temperature? What about the night temp. Also, if your light source is artificial, it could increase temperature inside the chamber (if growth chamber is used).  I don't know for sorghum but for rice, growing under controlled condition, D/N temperature is set at 29/21-deg C.

Good information Dr. Paul, but how this information could be used for fertigation scheduling for hydroponic.  This will depend on nutrient requirement of crop to get target yield, nutrient supplied in any other form and nutrient requirement  at different growth stages

I organise to international conference on sustainable agriculture and environment at August 10-12, 2017 in indonesia, so if you can come there we talk each other and you can disscuss to others. 

There is a lot of information available on the Internet. Most of them require classification. Certainly, you need to spend a lot of time for this purpose.

I agree with you Dr Tarafdar. If have to make an effective use of soil fertility variograms, we need to have crop nutrient requirement . And this information has to be soil, cultivar/ variety and desired yield specific....then only SSNM could be effectively use as a part  of precision nutrient management.We also have to  make distinction between nutrient uptake and nutrient removal..

Thank you sir, thank you  for the reply

It depends on the growth stage of the plant you are focusing on, or I would say that: you should state/describe which growth stage of the crop you are studying is affected by those microbes under the study. in this way you can specifically relate the effect to stages included in the 3-months period, otherwise< I would highly recommend to study the effect(s) throughout the whole period of the crop. good luck

We need to establish first , whether it is salinity or sodicity . If it is salinity , no need to apply gypsum or any chemical amendment . the question of applying gypsum as a chemical amendment comes only , when ESP is more than 15 and soil pH more than atleast 8.5..For removing salt from saline soils, we need only waterlogging followed by flushing /leaching of salts. For a sensitive crop like citrus ( hopefully kinnow mandarin raised on Jatti khatti rootstock) ) , any soil EC value more than 0.50-1.00 dS/m would be adversely affecting the growth as well as performance of the crop. USDA salinity standards would no longer aid in solving the salinity -induced adverse affects in citrus. 

Ten-Year Comparison of the Influence of Organic and Conventional Crop Management Practices on the Content of Flavonoids in Tomatoes

Alyson E. Mitchell ,*† Yun-Jeong Hong ,† Eunmi Koh ,† Diane M. Barrett ,† D. E. Bryant ,§ R. Ford Denison ,#and Stephen Kaffka §

Department of Food Science and Technology and Department of Plant Sciences, One Shields Avenue, University of California Davis, Davis, California 95616, and Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, Minnesota 55108

J. Agric. Food Chem., 2007, 55 (15), pp 6154–6159

DOI: 10.1021/jf070344+

Publication Date (Web): June 23, 2007

Copyright © 2007 American Chemical Society

 

Abstract

Understanding how environment, crop management, and other factors, particularly soil fertility, influence the composition and quality of food crops is necessary for the production of high-quality nutritious foods. The flavonoid aglycones quercetin and kaempferol were measured in dried tomato samples (Lycopersicon esculentum L. cv. Halley 3155) that had been archived over the period from 1994 to 2004 from the Long-Term Research on Agricultural Systems project (LTRAS) at the University of California Davis, which began in 1993. Conventional and organic processing tomato production systems are part of the set of systems compared at LTRAS. Comparisons of analyses of archived samples from conventional and organic production systems demonstrated statistically higher levels (P < 0.05) of quercetin and kaempferol aglycones in organic tomatoes. Ten-year mean levels of quercetin and kaempferol in organic tomatoes [115.5 and 63.3 mg g-1 of dry matter (DM)] were 79 and 97% higher than those in conventional tomatoes (64.6 and 32.06 mg g-1 of DM), respectively. The levels of flavonoids increased over time in samples from organic treatments, whereas the levels of flavonoids did not vary significantly in conventional treatments. This increase corresponds not only with increasing amounts of soil organic matter accumulating in organic plots but also with reduced manure application rates once soils in the organic systems had reached equilibrium levels of organic matter. Well-quantified changes in tomato nutrients over years in organic farming systems have not been reported previously.

Keywords: Tomato; organic agriculture; conventional agriculture; long-term research; flavonoid; flavonol; quercetin; kaempferol

Introduction

Fruits and vegetables are rich in dietary vitamins, minerals, and fiber and are the primary source of flavonoids in the diet. Epidemiological studies suggest that flavonoids protect against cardiovascular disease (1) and, to a lesser extent, against cancer (2) and other age-related diseases such as dementia (3). Flavonoids encompass a large group of phenolic secondary plant metabolites that demonstrate potent in vitro antioxidant activity (4, 5) and display free radical scavenging activity (6). Most attempts to assign health-promoting activity mechanistically to the antioxidant action of individual flavonoids in foods have been unsuccessful (7) and suggest that other mechanisms are likely involved in the health-promoting activities of these compounds.

Secondary plant metabolites such as the flavonoids function in plant defense mechanisms against herbivory, pathogen stress, and UV-B radiation (8). Many of these compounds are also the primary pigments responsible for attracting pollinators and seed dispersers. Flavonoids are produced through the phenylpropanoid pathway in plants. The key enzyme that catalyzes the biosynthesis is phenylalanine ammonia-lyase. Environmental stresses including nutrient deficiency, wounding, pathogens, and UV radiation are known to activate the biosynthesis of phenylpropanoid compounds (9, 10). Given the increasing data in support of a role for phenolic plant metabolites in the prevention of cardiovascular and other chronic diseases, efforts are underway to improve their levels in plant foods through improved cultivar selection and genetic manipulations. Alternatively, the phenolic content of plants may be influenced by manipulating the agronomic environment in which they are grown (11−13).

Fundamental differences between organic and conventional production systems, particularly in soil fertility management, may affect the nutritive composition of plants, including secondary plant metabolites. Organic systems emphasize the accumulation of soil organic matter and fertility over time through the use of cover crops, manures, and composts and rely on the activity of a diverse soil ecosystem to make nitrogen (N) and other nutrients available to plants. Conventional farms utilize fertilizers containing soluble inorganic nitrogen and other nutrients, which are more directly available to plants. The availability of inorganic nitrogen in particular has the potential to influence the synthesis of secondary plant metabolites, proteins, and soluble solids. Stamp proposed that increased crop growth and development rates and greater biomass accumulation in well-fertilized crops would also correlate with decreased allocation of resources toward the production of starch, cellulose, and non-nitrogen-containing secondary metabolites (14). Given that many secondary plant metabolites are produced for defense against herbivores and are inducible by pathogens or wounding, possible differences in pest pressure between conventional and organic systems might also influence levels in food crops.

Both conventional and organic agricultural practices include combinations of farming practices that vary greatly depending upon region, climate, soils, pests and diseases, and economic factors guiding the particular management practices used on the farm. Many of these influences change continuously, so a steady-state condition may never be achieved on most farms (15). The dynamic nature of agricultural systems also makes adequately controlled comparisons of produce quality, free from confounding influences, experimentally challenging. Comparisons of produce from different types of farms, even if they are near each other, are affected by the numerous factors mentioned. Reviews of studies comparing the nutritional quality of conventionally and organically produced vegetables demonstrate inconsistent differences with the exception of higher levels of ascorbic acid (vitamin C) and less nitrate in organic products (16, 17). However, these data are difficult to interpret because cultivar selection and agronomic conditions varied widely and different methods of sampling and analysis were used in the investigations cited. In contrast, cropping system comparisons using long-term research plots that have been managed consistently over time provide a means to overcome many of the confounding factors associated with farm-based sampling. Additionally, the effects of changes over time in cropping system behavior can be evaluated using archived soil and plant samples, and a reasonable estimate of the causes of those changes can be made.

The present study is an example of the use of long-term research to address complex processes operating in cropping systems. Its specific objective was to compare the content of the flavonoids quercetin, kaempferol, and naringenin in tomato samples (Lycopersicon esculentum L. cv. Halley 3155) produced in conventional and organic cropping systems that had been archived over the period from 1994 to 2004 from the Long-Term Research on Agricultural Systems project (LTRAS) at the University of California Davis, which began in 1993 (http://ltras.ucdavis.edu). LTRAS was designed to detect and estimate changes in crop productivity trends and other factors correlated with sustainability, which result from differing irrigation and fertilization practices (18). It includes an organic cropping system in which maize and tomatoes are grown in rotation and compared to the same crops produced conventionally. This archive of tomato samples is unique in California and perhaps the world.

This study focused on tomatoes because the per capita consumption of tomatoes (8.1 kg per capita in 2003) and tomato products (31.1 kg per capita in 2003) in the United States is very high, second only to the potato (19). Tomatoes provide an important and significant source of vitamin C (19 mg/100 g of fresh weight), vitamin A (623 IU/100 g of fresh weight), lycopene (3.0 mg/100 g of fresh weight), and flavonoids (20, 21). The main flavonoids found in tomatoes are quercetin, kaempferol, and naringenin (Figure 1). Quercetin predominates, with levels ranging from 0.03 to 2.77 mg/100 g in fresh tomatoes and 4.77 mg/100 g in processed tomato products (22). Levels of kaempferol range from 0.01 to 0.06 mg/100 g in fresh and processed tomatoes (22). Figure 1 Structures of the flavonoid aglycones of quercetin, keampferol, and naringenin.

Materials and Methods

Chemicals and Samples. Quercetin dihydrate (3,5,7,3‘,4‘-pentahydroxyflavone dihydrate, 98%), morin hydrate (3,5,7,2‘,4‘-pentahydroxyflavone hydrate, 95%), and tert-butylhydroquinone (TBHQ, 97%) were purchased from Aldrich Chemical Co., Inc. (Milwaukee, WI). Kaempferol (3,5,7,4‘-tetrahydroxyflavone, 95%) and naringenin (4‘,5,7-trihydroxyflavone, 95%) were obtained from Sigma Chemical Co. (St. Louis, MO), and Indofine Chemical Co., Inc. (Hillsborough, NJ), respectively. All solvents used were of HPLC grade. Ethanol was purchased from Spectrum Chemicals (Gardena, CA).

Tomato Cultivation in the LTRAS Cropping Systems. Following uniform cropping with Sudan grass (Sorghum vulgare L.) in 1992 and 1993, 10 different cropping systems were established in 1993 using 0.4 ha plots (18). Each cropping system was replicated three times, and both crops or phases of the two-year rotations were present each year. Plots were large enough to allow for the use of commercial-scale farm equipment. Irrigation amounts were measured using flow meters located at each irrigated plot. Systems differ in the amount of irrigation received (rain fed or irrigated), in the amounts of nutrients applied as fertilizers, and in organic matter applied to the soil as crop residues, winter legume cover crops, and/or composted manure. Conventional plots received herbicides and other pesticides as needed, whereas organic crops received only organically approved pesticides, such as sulfur and Bt compounds. Crop yields and total biomass were measured every year and analyzed for total N and C. Sample archiving included yearly plant and fruit samples from all cropping systems and time zero and subsequent soil samples collected every few years. Systems rather than single inputs were compared, so a valid comparison required that each system be managed carefully to achieve its potential yields. For example, both the conventional and organic maize/tomato systems had the same tomato cultivar (Halley 3155) and were irrigated similarly as needed, but the lower percent availability of organic N sources can require more total N input to meet crop N needs (24). The same cultivar was used throughout the 12-year period. The systems compared are model systems, chosen to include representative crops rather than more complex, changeable crop rotations. California farmers rarely follow fixed crop rotations as markets change, and organic farmers especially tend to have more complex rotations than the one studied at LTRAS.

Crop management practices follow best management practice guidelines in the region. Conventional tomatoes received 50 kg ha-1 of an N−P−K starter fertilizer and 118 kg ha-1 of ammonium nitrate as side dressing. A combination of tillage and herbicides was used for weed control. Aphids, mites, and stinkbugs occur periodically and were controlled as necessary, similar to practices in commercial fields. In both treatments, processing tomatoes were transplanted at the rate of 22500 plants ha-1 (10000 per acre). Transplanting in the organic treatment followed incorporation of a winter legume cover crop consisting of hairy vetch (Vicia villosa Roth) and field peas (Pisum sativum L.). Transplanting of all plots occurred within a period of 2−4 days in spring, commonly around the middle of April. Prior to incorporation of the cover crop, 9 Mg ha-1 of composted poultry manure currently is top-dressed and incorporated with the cover crop. The amount of N present in cover crops varies from year to year, but, typically, organic plots currently receive between 240 and 260 kg of N ha-1 year in addition to the N fixed by the legume cover crop (24). During the first three cropping cycles, to more rapidly increase soil organic matter levels and soil fertility, 19 Mg ha-1 of composted manure was added to tomato crops. This was reduced after organic matter levels had increased to a near constant level (24). Tomatoes were harvested each year when the field as a whole reached 90% ripe fruit. A commercial tomato harvester was used for main plot harvests. Similar methods of transplanting and plant populations were used for conventional plots as well, and transplanting of all plots occurred within a period of 2−4 days in spring, commonly around the middle of April.

Sampling and Preparation of Plant Material. Immediately prior to harvest of the main plot, samples for the archive were collected from four 3.1 m2 subsample areas (subplots) within the larger main plots. Total plant biomass and the yield of the red ripe fruit were determined for each subplot. A random sample of 20 ripe fruits from the four subplots was washed and oven-dried at 60 °C, ground, and stored in glass containers in the dark at 20 °C until use. Samples from conventional and organic plots from even numbered years (1994−2004) were chosen for flavonoid analysis. Three of the subplots (n = 3) for each treatment (three organic; three conventional) were analyzed each of the even years (1994−2004). These subplot samples were analyzed in triplicate.

Flavonoid Analysis. Flavonoid analysis followed the general method of Merken and Beecher (25) as modified by Chassy et al. for fresh processing tomatoes (26). Flavonoid glycosides were hydrolyzed to their corresponding agylcones, which were subsequently measured using HPLC. Briefly, 1 g of pestle-pulverized, air-dried tomato sample was combined with 100 mL of 1.6 g/L tert-butylhydroquinone, 1.2 N hydrochloric acid, and 50% methanol (MeOH). To this mixture was added 0.5 mL of a 1 mg/mL standard of luteolin as an internal standard. Internal standard recovery was 92−93% for luteolin. Samples were refluxed for 4 h at 100 °C in a 250 mL round-bottom flask. Four hours of reflux time, in 1.2 N hydrochloric acid, was determined as the optimal condition for maximal recoveries of quercetin, kaempferol, and naringenin in these samples. An aliquot was removed, diluted 50:50 v/v with MeOH (200 μL), and filtered through a 0.5 mL of 25 μm MC Ultrafree-MC filter (Millipore, Bedford, MA). Flavonoids were separated using a Hewlett-Packard 1090 HPLC equipped with a variable wavelength diode array detector and Chemstation (LC 3D rev. A.08.03) software (Agilent, Palo Alto, CA) monitoring 370 nm. Reversed phase HPLC was performed using a 250 × 4.6 mm i.d., 5 μm Zorbax XDB-C18 column and a 12.5 × 4.6 mm i.d. 5 μm Zorbax XDB-C18 precolumn (Agilent). The mobile phase consisted of 0.05% trifluoroacetic acid (TFA) in water (solvent A), 0.05% TFA in MeOH (solvent B), and 0.05% TFA in acetonitrile (solvent C). Separations were effected by a series of linear gradients using a flow rate of 1.0 mL/min as follows: 90−85% A, 6−9% B, 4−6% C, 0−5 min; 85−71% A, 9−17.4% B, 6−11.6% C, 5−30 min; 71−0% A, 17.4−85% B, 11.6−15% C, 30−60 min. The linear ranges of quantitation for quercetin and kaempferol were 0.5−10 and 0.1−10 μg/mL respectively.

Statistical Analysis. Data were analyzed using SAS software version 9.1 (SAS Institute, Cary, NC). Specifically, PROC Mixed and regression were used to analyze treatment differences and create single degree of freedom contrasts for differences between systems (27).

Results

The mean level of the flavonoids quercetin, naringenin, and kaempferol agylcones (mg g-1 of DM) were significantly higher (p < 0.001) in samples from the organic cropping system as compared to samples from the conventional cropping system (Table 1). Quercetin was the most abundant flavonoid in both organic (115.5 ± 8.0 mg g-1 of DM) and conventional (64.6 ± 2.4 mg g-1 of DM) tomatoes. In conventional tomatoes, kaempferol (32.06 ± 1.94 mg g-1 of DM) and naringenin (30.2 ± 1.57 mg g-1 of DM) levels were comparable, whereas levels of kaempferol (63.3 ± 5.21 mg g-1 of DM) were significantly higher than naringenin levels (39.6 ± 1.58 mg g-1 of DM) in organic tomatoes. Absolute differences in the flavonoids increased with time in both systems, with the largest differences observed in the last 4-year period (Figures 2 and 3). Figure 2 Quercetin (·), naringenin (○), and kaempferol (▾) levels in tomatoes derived from conventional cropping systems at LTRAS from 1994 to 2004 (mg g-1of DM). Values are given with standard deviations.

Figure 3 Quercetin (·), naringenin (○), and kaempferol (▾) levels in tomatoes derived from organic systems at LTRAS from 1994 to 2004 (mg g-1 of DM). Values are given with standard deviations.

Table 1. Mean Flavonoid Concentrations in Archived Samples from the LTRAS Experiment (1994−2004) and Single Degree of Freedom Contrasts between Conventional and Organic Farming Systems

 

mean (SD) (mg g-1 of DM)

flavonoid

conventional

organic

F

p

quercetin

64.6 (2.49)

115.5 (8.0)

108.16

<0.0001

naringenin

30.2 (1.57)

39.6 (1.58)

66.36

<0.0001

kampferol

32.06 (1.94)

63.3 (5.21)

96.64

<0.0001

Figure 4 compares the quercetin and kaempferol means to N applications over this 10-year period. Increases in quercetin and kaempferol content appear to be correlated in time with changes in manure application rates, which were reduced in the organic system in 1998 from an average of 45 to 18 Mg ha-1over the 2-year maize/tomato cycle. Conventional maize/tomato rotation crops received 230 kg of N ha-1 for maize and 160 kg of N ha-1 for tomatoes in each year. Levels of quercetin and kaempferol where highest in years 2000, 2002, and 2004. Figure 5 shows tomato yield from 1994 to 2004 in organic and conventional plots. On average, yields were not significantly different between the two systems, but there was less year-to-year variation in the organic systems (28, 29). Figure 4 Changes in flavonoid levels averaged over 10 years of the LTRAS trial, and changes in N inputs over time to the tomato systems (1994−2004).

Figure 5 LTRAS tomato yields (Mg of fresh weight) from 1994 to 2004.

Discussion

The content of flavonoids appears to have increased over time in the archived tomato samples in both the conventional and organic systems (Figures 2 and 3). The rates of increase of quercetin and kaempferol were much lower in the conventional system compared to the organic system. For the conventional system, regression analysis of mean values of flavonoid concentration versus time suggests an increase of 1.9 mg g-1 year-1 for kaempferol (se = 0.34, r2 = 0.65) and 2.0 mg g-1 year-1 for quercetin (se = 0.57, r2 = 0.43). Naringenin increased at a rate of 1.35 mg g-1 year-1(se = 0.33, r2 = 0.51). Alternatively, these rates of increase can be interpreted as rates of deterioration of flavonoid content in storage with time. During the 10-year period analyzed, farming practices in the conventional system, including N fertilization and the tomato variety grown, did not change, and there was little accumulation of organic matter or other obvious changes in soil quality over that period in conventional plots (24). Therefore, it appears most likely that flavonoids declined slowly with time in storage. The stability of flavonoids has been documented in onions stored for 24 weeks (30) and in apples stored for up to 30 weeks (31). We assume that the rate of decline in storage is identical in both organic and conventional samples. If that is the case, then there is a significant difference in the amount of flavonoids occurring in ripe fruit at harvest between the two systems.

Bongue-Bertlesman and Philips found that N-deficient tomato plants had significantly greater flavonoid content in their leaves (32). Chassy et al. reported significantly higher mean levels of soluble solids, flavonoids, total phenolics, and ascorbic acid in organic tomatoes as compared to their conventional counterparts grown in model plots over a 3-year period (26). However, year-to-year variation in this study was significant, and only the levels of kaempferol were statistically higher in organic tomatoes for all three years (26). Toor et al. also examined the influence of nutrient source on antioxidant components and antioxidant activity of greenhouse-grown tomatoes (11). These tomatoes were grown with mineral nutrient solutions (containing NH4+ and NO3-), chicken manure, and grass-clover mulch. The mean total phenolic and ascorbic acid contents of tomatoes grown using grass-clover mulch (29%) and chicken manure (17.6%) were higher than those of the tomatoes grown with the mineral nutrient solutions and demonstrate that nutrient source can play a role in determining the levels of antioxidants in tomatoes.

Soil organic matter (SOM) levels in the organic system at LTRAS are currently significantly higher in the organic plots than in the conventional ones (18). SOM may have reached a quantitative limit of accumulation by 1997 or 1998 (24, 28), but changes in SOM quality may still be occurring (22). At about the time SOM reached a limit of accumulation, the amount of composted manure applied to organic plots was reduced. Over the 2-year crop rotation (maize/tomato), the amount was reduced from approximately 45 Mg ha-1 on average to 18 Mg ha-1. Similar amounts of N continued to be applied as green manure cover crops grown during the winter season, subject to year-to-year variation in cover crop growth. Figure 4 compares the amounts of quercetin and kaempferol in conventional and organic systems to estimated N applications over the 12-year period. Significant increases in quercetin and kaempferol content appear to be correlated in time with the cumulative effects of changes in manure application rates, resulting in lower total N application amounts to organic plots over the last 6 years as compared to the first 6 years. These changes did not affect LTRAS tomato yield (Figure 5), and they did not consistently affect color or soluble solids, other secondary quality characteristics commonly assessed by tomato processors in fresh samples (29).

Flavonoid content in tomatoes seems to be related to available N (3, 11). Plants with limited N accumulate more flavonoids than those that are well-supplied. If differences in flavonoid content reflect fundamental differences in the behavior of soil N between conventional and organic systems, then the N available to tomatoes late in the season may have declined in organic plots in recent years in response to the cumulative effects of a decrease in compost application rates.

The LTRAS project, a carefully managed long-term research project focusing on cropping systems, is a useful basis for detecting and determining the magnitude of differences in tomato quality. The differences detected appear to be correlated with differences in soil fertility management associated with conventional and organic farming systems. These comparisons are free of confounding factors such as soil type differences, differing and variable crop management histories, uneven amounts of time that systems have been managed organically or convetionally, differing levels of farm management skill among farmers, cultivar differences, irrigation, harvesting, sample handling, and other factors that affect the usefulness of most previous comparisons of fruit quality between conventional and organic farming systems. Instead, differences can be attributed primarily to contrasting soil fertility management practices between the conventional and organic systems. The two systems produced tomatoes with differing flavonoid contents within individual years, and these differences increased with time. We suggest that it is the behavior and quantity of N in the organic and conventional systems that most strongly influence these differences (11, 30, 33). If so, then overfertilization (conventional or organic) might reduce health benefits from tomatoes.

This article references 33 other publications.

(1) Hertog, M. G. L.; Hollman, P. C. H. Potential health effects of the dietary flavonol quercetin. Eur. J. Clin. Nutr. 1996, 50, 63−71. 

(2) Knekt, P.; Kumpulainen, J.; Jarvinen, R.; Rissanen, H.; Heliovaara, M.; Reunanen, A.; Hakulinen, T.; Aromaa, A. Flavonoid intake and risk of chronic disease. Am. J. Clin. Nutr. 2002, 76, 560−568. 

(3) Commenges, D.; Scotet, V.; Renaud, S.; Jacqmin-Gadda, H.; Barberger-Gateau, P.; Dartigues, J. F. Intake of flavonoids and risk of dementia. Eur. J. Epidemiol. 2000, 16, 357−363. 

(4) Duthie, G.; Crozier, A. Plant-derived phenolic antioxidants. Curr. Opin. Lipidol. 2000, 11, 43−47. 

(5) Pietta, P. Flavonoids as antioxidants. J. Nat. Prod. 2000, 63, 1035−1042. 

(6) van Acker, S. A. B. E.; Tromp, M. N. J. L.; Haenen, G. R. M. M.; van der Vijgh, W. J. F.; Bast, A. Flavonoids as scavengers of nitric oxide radical. Biophys. Biochem. Res. Commun. 1995, 214, 755−759. 

(7) Williamson, G.; Manach, C. Bioavailability and bioefficacy of polyohenols in humans. II. Review of 93 intervention studies. Am. J. Clin. Nutr. 2005, 81, 243S−255S. 

(8) Harborne, J. B.; Williams, C. A. Advances in flavonoid research since 1992. Phytochemistry 2000, 55, 481−504. 

(9) Dixon, R.; Paiva, N. Stress-induced phenylpropanoid metabolism. Plant Cell 1995, 7, 1085−1097. 

Dey, P. M.; Harborne, J. B. Plant Biochemistry; Academic Press: London, U.K., 1997. 

(11) Toor, R. K.; Savage, G. P.; Heeb, A. Influence of different types of fertilisers on the major antioxidant components of tomatoes. J. Food Compos. Anal. 2006, 19, 20−27. 

(12) Howard, L. R.; Pandjaitan, N.; Morelock, T.; Gil, M. I. Antioxidant capacity and phenolic content of spinach as affected by genetics and growing season. J. Agric. Food Chem. 2002, 50, 5891−5896. 

(13) Connor, A. M.; Luby, J. J.; Tong, C. B. S.; Finn, C. E.; Hancock, J. F. Genotypic and environmental variation in antioxidant activity, total phenolic content, and anthocyanin content among blueberry cultivars. J. Am. Soc. Hortic. Sci. 2002, 127, 89−97. 

(14) Stamp, N. E. Out of the quagmire of plant defense hypotheses. Q. Rev. Biol. 2003, 78, 23−55. 

(15) Antle, J. M.; Capalbo, S. M.; Elliott, E. T.; Hunt, H. W.; Mooney, S.; Paustian, K. H. Research needs for understanding and predicting the behavior of managed ecosystems: lessons from the study of agroecosystems. Ecosystems 2001, 4, 723−735. 

(16) Bourn, D.; Prescott, J. A comparison of the nutritional value, sensory qualities, and food safety of organically and conventionally produced foods. Crit. Rev. Food Sci. Nutr. 2002, 42, 1−34. 

(17) Brandt, K.; Mølgaard, J. P. Organic agriculture: does it enhance or reduce the nutritional value of plant foods? J. Sci. Food Agric. 2001, 81, 924−931. 

(18) Denison, R. F.; Bryant, D. C.; Kearney, T. E. Crop yields over the first nine years of LTRAS, a long-term comparison of field crop systems in a Mediterranean climate. Field Crops Res. 2004, 86, 267−277. 

(19) Lucier, G.; Lin, B. H.; Allshouse, J.; Kantor, L. S. Factors affecting tomato consumption in the United States.Vegetables and Specialties/VGS 282; Economic Research Service/USDA: Washington, DC, 2000; pp 26−32. 

USDA Economic Research Service Briefing Room: Tomatoes; available athttp://www.ers.usda.gov/Briefing/Tomatoes/ (accessed March 7, 2006). 

(21) USDA Agricultural Research Service Nutrient Database for Standard Reference, release 18; available athttp://www.nal.usda.gov/fnic/foodcomp (accessed Oct 1, 2005). 

(22) USDA Agricultural Research Service Database for the Flavonoid Content of Selected Foods, release 2; available at http://www.nal.usda.gov/fnic/foodcomp (accessed Oct 1, 2005). 

(23) Deleted in proof. 

(24) Kong, A. Y. Y.; Six, J.; Bryant, D. C.; Denison, R. F.; van Kessel, C. The relationship between carbon input, aggregation, and soil organic carbon stabilization in sustainable cropping systems. Soil Sci. Soc. Am. J.2005, 69, 1078−1085. 

(25) Merken, H. M.; Beecher, G. R. Liquid chromatographic method for the separation and quantification of prominent flavonoid aglycones. J. Chromatogr., A 2000, 897, 177−184. 

(26) Chassy, A. W.; Bui, L.; Renaud, E. N. C.; van Horn, M.; Mitchell, A. E. A three-year comparison of the content of antioxidant microconstituents and several quality characteristics in organic and conventionally managed tomatoes and bell peppers. J. Agric. Food Chem. 2006, 54, 8244−8252. 

(27) Little, R. C.; Milliken, G. A.; Stroup, W. W.; Wolfinger, R. D. SAS System for Mixed Models; SAS Institute: Cary, NC, 1996. 

(28) Martini, E. A.; Buyer, J. S.; Bryant, D. C.; Hartz, T. K.; Denison, R. F. Yield increases during the organic transition: improving soil quality or increasing experience? Field Crops Res. 2004, 86, 255−266. 

(29) Kaffka, S. R.; Bryant, D. C.; Denison, R. F. Comparison of organic and conventional maize and tomato cropping systems from a long-term experiment in California. In Proceedings of the First Scientific Conference of the International Society for Organic Farming Research; Koepke, U., Neuhoff, D., Cornish, P., Lockeretz, W., Wiler, H., Eds.; Institute of Organic Agriculture: Bonn, Germany, 2005; pp 218−221. 

Price, K. R.; Bacon, J. R.; Rhodes, M. J. Effect of storage and domestic processing on the content and composition of flavonol glucosides in onion (Allium cepa). J. Agric. Food Chem. 1999, 45, 938 −942. 

(31) van der Sluis, A. A.; Dekker, M.; de Jager, A.; Jongen, W. M. F. Activity and concentration of polyphenolic antioxidants in apple: effect of cultivar, harvest year, and storage conditions J. Agric. Food Chem. 2001, 49, 3606−3613. 

(32) Bongue-Bartelsman, M.; Phillips, D. A. Nitrogen stress regulates gene expression of enzymes in the flavonoid biosynthetic pathway of tomato. Plant Physiol. Biochem. 1995, 33, 539−546. 

(33) Lumpkin, H. M. A Comparison of Lycopene and Other Phytochemicals in Tomatoes Grown under Conventional and Organic Management Systems; Technical Bulletin 34; AVRDC: Tainan, Taiwan, 2005. 

 

 

Dear all, thank you very much.

I answer to Paul - no, there were not clear toxicity symptoms on wheat. The experiment was carried out on alluvial moderately fine and fine soils, very fertile. Among the factors of exepriments was N and N+S treatments. N treatment with ammonium nitrate, N+S with commercial fertilizer produced from mixing of ammnonium nitrate and ammonium sulfate (i.e.- the form of N was not exactly the same in compared tratments). When speaking about yields, they were slightly smaller (sometimes significantly, sometimes not) in N+S comparing with N. For this reason one person interpreted this as "S toxicity". Actually, I cannot agree with such interpretation, because, in my opinion, lower yields do not imply toxicity. I think other factors could cause such situation (for example form of  N, perhaps in relation to weather conditions etc.) or other. Certainly, S as any other nutrient may be toxic (many thanks to Anoop), but probably not in this case, because, the S dose did not exceed clearly estimated S demand of the crop.

With regard to possible efeect of sulphates on soil EC. I think in conditions of Poland, with humid climate (precipitations exceeding potential evapotranspiration) such effect probably rarely occurs (natural salinity of soils rather does not occur in Poland, with exception of some effects of human activity or neighbourhood of the sea). In case of our wheat such "salinity effect" would result from application of all fertilizers, but rather not S treatment (the amount of N added in both treatments was greater, than amount of S, both in readily soluble form).

Please find this pdf file

ICARDA scientists are working on this area.

1. Different osmolytes application,

2. Silicon foliar spray

3. Use of specific PGPR  

 Will be useful during drought stress

Interesting question . Here is the abstract of  latest work...

Abstract: Effective sustainable algal cultivation techniques are essential for mass production of the marine microalga Tetraselmis for biofuel and array of co-products. The phycospheric communities affect the microalgal growth and metabolism through various allelochemical and nutrient interactions; hence, their potential to affect the quantity and quality of both biomass and bioproducts is significant. In the present study, we have screened the phycospheric communities of biofuel producing Tetraselmis striata (KCTC1432BP). A total of 26 bacterial strains were isolated and identified from the phycosphere of T. striata mass culture. Then, each bacterial strain was tested in co-cultivation conditions with T. striata for evaluating its growth promoting and inhibitory effects. Among these all strains, two promising strains (Pelagibaca bermudensis KCTC 13073BP and Stappia sp. KCTC 13072BP) were selected because of their maximum growth promoting effects and mutualistic interactions. The growth rate, biomass productivity, lipid contents, and fatty acids were analyzed during their combined growth in O3 media and compared with axenic growth of T. striata. Later, growth promoting mechanisms in the co-cultivation environment were investigated for these promising bacterial strains under replete and limited conditions of nutrients (nitrate, phosphate, and vitamin B12). The growth promoting potential of P. bermudensis was illustrated by the two fold enhancement in biomass productivity. These bacteria are promising for microalgal cultivation without any negative effects on the native seawater bacterial communities, as revealed by next generation sequencing analysis. This study represents, to date, the first report highlighting the role of phycospheric growth promoting bacteria of promising biofuel feedstock T. striata. Source ; Frontiers in Plant Science ,doi: 10.3389/fpls.2017.0028

Dear Rao, 

Yields of maize and soya in my region range from 8 to 12 t / ha and 2.5 to 6 t / ha for both crops. In general, the costs per hectare to produce maize and soy do not vary considerably for a minimum and maximum yield. This cost variation is approximately 10-15% above or below the average cost. As for grain prices, it only has a high impact on economic performance when yields are below the minimum mentioned above. Otherwise, the economic performance of both crops is linearly related to yield. This assertion originates from the analysis of economic results of companies during 5 or 6 agricultural cycles.

I hope the clarification helps, any doubt we are in contact.

Regards

Interesting discussion..

Abstract

Introduction. Residues of previous crops provide a valuable amount of organic matter that can be used either to restore soil fertility or for external use. A better understanding of the impact of crop residue management on the soil-water-plant system is needed in order to manage agricultural land sustainably. This review focuses on soil physical aspects related to crop residue management, and specifically on the link between soil structure and hydraulic properties and its impact on crop production.

Literature. Conservation practices, including crop residue retention and non-conventional tillage, can enhance soil health by improving aggregate stability. In this case, water infiltration is facilitated, resulting in an increase in plant water availability. Conservation practices, however, do not systematically lead to higher water availability for the plant. The influence of crop residue management on crop production is still unclear; in some cases, crop production is enhanced by residue retention, but in others crop residues can reduce crop yield.

Conclusions. In this review we discuss the diverse and contrasting effects of crop residue management on soil physical properties and crop production under a temperate climate. The review highlights the importance of environmental factors such as soil type and local climatic conditions, highlighting the need to perform field studies on crop residue management and relate them to specific pedo-climatic contexts. Source :Volume 20 (2016) Numéro spécial 1 : AgricultureIsLife

 Abstract : Soil labile C and N fractions can change rapidly in response to management practices compared to non-labile fractions. High variability in soil properties in the field, however, results in nonresponse to management practices on these parameters. We evaluated the effects of residue placement (surface application [or simulated no-tillage] and incorporation into the soil [or simulated conventional tillage]) and crop types (spring wheat [Triticum aestivum L.], pea [Pisum sativum L.], and fallow) on crop yields and soil C and N fractions at the 0–20 cm depth within a crop growing season in the greenhouse and the field. Soil C and N fractions were soil organic C (SOC), total N (STN), particulate organic C and N (POC and PON), microbial biomass C and N (MBC and MBN), potential C and N mineralization (PCM and PNM), NH4-N, and NO3-N concentrations. Yields of both wheat and pea varied with residue placement in the greenhouse as well as in the field. In the greenhouse, SOC, PCM, STN, MBN, and NH4-N concentrations were greater in surface placement than incorporation of residue and greater under wheat than pea or fallow. In the field, MBN and NH4-N concentrations were greater in no-tillage than conventional tillage, but the trend reversed for NO3-N. The PNM was greater under pea or fallow than wheat in the greenhouse and the field. Average SOC, POC, MBC, PON, PNM, MBN, and NO3-N concentrations across treatments were higher, but STN, PCM and NH4-N concentrations were lower in the greenhouse than the field. The coefficient of variation for soil parameters ranged from 2.6 to 15.9% in the greenhouse and 8.0 to 36.7% in the field. Although crop yields varied, most soil C and N fractions were greater in surface placement than incorporation of residue and greater under wheat than pea or fallow in the greenhouse than the field within a crop growing season. Short-term management effect on soil C and N fractions were readily obtained with reduced variability under controlled soil and environmental conditions in the greenhouse compared to the field. Changes occurred more in soil labile than non-labile C and N fractions in the greenhouse than the field.

I believe, the important thing is that urea should not be applied at the surface of the soil.  Even if urea is placed at 1-2 cm depth, it is not prone to ammonia volatilization losses.  Thus, depending upon the availability of machinery for urea application, it can be applied from say 2 cm to 5-6 cm deep in the soil. Urea placed deep in the soil even by its application just before applying irrigation is also good; the irrigation water transports urea to a depth.  But it may not be feasible in maize. 

I support Dr. Kundu's recommendation of buckwheat for clay soils. Buckwheat is effective at aggregating clays so that the soil is more friable the following season. The challenge is that buckwheat roots are very fine, so they will not grow well in a compacted or waterlogged soil, and clays are quite prone to both of those conditions.

My experience with buckwheat is from the temperate areas where buckwheat is commonly raised. There may be challenges to using it as a cover crop in an area as tropical as Sulawesi.

It depends on what your cages are being used for and the design life for the structure.

The attached paper describes some work we did many years ago on fouling control coatings and aquaculture nets.  Since  then there have been significant improvements in the silicone based fouling release coatings and there is at least one product that will prevent fouling.  Your choice will probably be determined by their active ingredients which can be found on their MSDS.

I hope this helps

Kind regards

Geoff Swain

Good points Dr. Andrew. Paulownia is one of the fastest growing trees in the world, capable of growth rates of well over seven feet per year as a seedling! But while it’s highly appreciated and cultivated in Asia, Paulownia has come to be considered an invasive species in the United States.

 This type of cropping leads to an improvement in the fertility of the soil and hence, increase in crop yield because when the two crops are properly chosen the products and refuse from one crop plant help in the growth of the other crop plant and vice-versa. Mixed cropping is an insurance against crop failure due to abnormal weather conditions.

There is strong relationship. Increasing Agricultural Productivity and Resilience Through Effective Dissemination of Agro-weather Advisory Services is followed in many countries.

Sowing of okra around the tomato crop is the best trap crop for control of insect populations of whitefly, jassid etc.

Organic acids such as citrate, malate and oxalate are able to desorb or solubilise fixed soil P, making it available for plant uptake. Organic acids also chelate Al3+to render it non-toxic, and are, therefore, involved in Al tolerance mechanisms. The role of organic acids exuded from roots in improving plant P uptake and Al-tolerance in acid soils has been documented. Several workers have attempted to understand how P deficiency or exposure to Al3+activates or induces organic acid efflux at the molecular level, with the aim of improving P acquisition and Al tolerance by conventional plant breeding and by genetic engineering. At the agronomic level, it is desirable that existing crop and pasture plants with enhanced soil-P uptake and tolerance to Al due to organic acid exudation are integrated into farming systems.

Interesting discussion..

From the 1920s to the late 1940s, a great and largely un-sung hero of agriculture, Dr. William Albrecht, did a lot of experimenting with different ratios of nutrient cations, the Calcium, Magnesium, Potassium and Sodium mentioned above. He and his associates, working at the University of Missouri Agricultural Experiment Station, came to the conclusion that the strongest, healthiest, and most nutritious crops were grown in a soil where the soil's CEC was saturated to about 65% Calcium, 15% Magnesium, 4% Potassium, and 1% to 5% Sodium. (No, they don't add to 100%; we'll get to that.) This ratio not only provided luxury levels of these nutrients to the crop and to the soil life, but also strongly affected the soil texture and pH.

The percentage of the CEC that a particular cation occupies is also known as the base saturation percentage, or percent of base saturation, so another way of describing Albrecht's ideal ratio is that you want 65% base saturation of Calcium, 15% base saturation of Magnesium etc. Don't get too hung up on these percentages; they are general guidelines and can vary quite a bit depending on soil texture and other factors.

It's still a little-known fact that the Calcium to Magnesium ratio determines how tight or loose a soil is. The more Calcium a soil has, the looser it is; the more Magnesium, the tighter it is, up to a point. Other things being equal, a high Calcium soil will have more Oxygen, drain more freely, and support more aerobic breakdown of organic matter, while a high Magnesium soil will have less Oxygen, tend to drain slowly, and organic matter will break down poorly if at all. In a soil with Magnesium higher than Calcium, organic matter may ferment and produce alcohol and even formaldehyde, both of which are preservatives. If you till up last years corn stalks and they are still shiny and green, you may have a soil with an inverted Calcium/Magnesium ratio. On the other hand, if you get the Calcium level too high, the soil may lose its beneficial granulation and structure and the excessive Calcium will interfere with the availability of other nutrients. If you get them just right for your particular soil, you can drive over the garden and not have a problem with soil compaction....

Rice Co has a WG formulation that does not presents those problems 

Sir, I have been planning to develop an index for ozone dose and yield response, taking in consideration of different ozone concentrations ambient and artificial as well. I am still in the preliminary stage of my experiment. As you yourself has stated that ascorbic acid is highly effective, I have not been able to find much literature about the usage of ascorbic acid as masking agent in Indian context, most of the studies focuses using EDU rather than ascorbic acid, if you could share some literature of ascorbic acid being used, that would be a great help. Regards, and greetings for dusshera.

Thank you for your valuable guidance...!!!

In the short-term farmers are advised to:

 Uproot and remove affected plants

 Avoid growing maize in consecutive seasons, opting for crop rotation or grow alternative crops

 Be aware of specific season and planting time to avoid spreading of the disease

 Apply good agronomic practices

 Chemical spraying of vector under specific circumstances

In the long-term both technical and programmatic interventions are required for more sustainable solutions. 

 Technical interventions:

o Investment in promotion of good agricultural practices

o Breeding of resistant or tolerant seeds

 Programmatic interventions:

o Regional dialogue for coherent responses and regulations with a role for private sector

stakeholders

o Expansion of markets for alternative crops and diversification of food habits

o Effective and efficient surveillance systems need to be set up

For growers the classification of vegetable crops by similarities in their temperature requirements (Thermo-classification) or by their ability to withstand frost (Hardy ness classification) assists growers in planning their planting schedules. However hardy only refers to frost and some hardy vegetables will not withstand summer drought, while some tender crops do not thrive in cool weather even when there is no frost.  On the one side vegetable crops are defined on the basis of hardiness and on another side not unlike hardyness thermo-classification is also based on temperature. The difference is that crops are classified according to their optimum temperature requirements and are divided into two groups either as cool temperature or warm temperature crops. Cool temperature crops have an optimum temperature of 12-20oC and are able grow as low as 1oC, no mention of their ability to withstand frost are given in this classification. Warm temperature crops have an optimum of 18-20 oC Cool temperature crops are as follows: Green peas, lettuce, cabbage, cauliflower, broccoli, onions and spinach are all ‘cold season ’ crops. ‘Warm season’ crops are; Beans, cucumber, eggplant, okra, pepper, summer squash, watermelon, and tomatoes. This system of classification gives the grower an indication of the crops ability to withstand high temperatures but nothing in regards to frost. In order to have a clear idea on which crop to use when planning a planting schedule it is advised that the grower use the ‘hardyness classification’ in conjunction with the thermo-classification.

 This is not uncommon in plants,  various species exhibits response to temperature in respect of flower bearing e.g. prunus  spp, moreover, some physical factors could cause effects on % maleness/femaleness in flower as well.

attached some reference for the yield and growing periods recommended to Lettuce and other vegetables

Basically the soil texture, soil organic matter and the occurrence of natural lime in the soil (acid soils and alkaline soils).

Dear Manoj Gupta,

Agricultural Drones Relatively cheap drones with advanced sensors and imaging capabilities are giving farmers new ways to increase yields and reduce crop damage. “drones” means to Kunde and the growing number of farmers like him is simply a low-cost aerial camera platform: either miniature fixed-wing airplanes or, more commonly, quadcopters and other multibladed small helicopters. These aircraft are equipped with an autopilot using GPS and a standard point-and-shoot camera controlled by the autopilot; software on the ground can stitch aerial shots into a high-¬resolution mosaic map. Whereas a traditional radio-¬controlled aircraft needs to be flown by a pilot on the ground, in Kunde’s drone the autopilot (made by my company, 3D Robotics) does all the flying, from auto takeoff to landing. Its software plans the flight path, aiming for maximum coverage of the vineyards, and controls the camera to optimize the images for later analysis.

Find potentially yield limiting problems in a timely fashion.

While all farmers know the value of scouting their crops few actually have time to cover the acres on foot.

At an average of $2 per acre for a walking visual inspection or an aerial survey to take an image of crop fields, the  purchase of an aerial helicopter drone can be met quickly. In most operations, the  drones can be achieved in a crop season or less, leaving you owning a drone that reduces your operating costs and improves your crop yield by giving you the timely information you need for quick management intervention.

The drone  can be very complex to set-up and operate, but with our present standards we allow new operators to have confidence in operating from the beginning.

Draw field borders for flight pattern

Seeing the true health of your field in a color contrast allows you to see how much sunlight is being absorbed by the crop canopy.

As an added safety net with the flip of switch your Precision Drone will return to its original take off location.

Regards,

Prem Baboo

Before adaptation measure, you need to find out following answers:

(1) Year-round normalized (say average of 30 years daily data) monthly maximum and minimum temperatures.

(2) Seasonal variations (intra and inter seasonal) in temperatures and rainfall.

(3) Available heat tolerant varieties (for example Vigna radiata can tolerate 45^oC).

(4) Depending on C₃ or C₄ type plants response to increased CO₂ will vary.

(5) Once you get the above facts, you can think of shifting planting time depending on rainfall or available irrigation water.

(6) Instead of rice crop you can think of transforming those land to mango orchard, guava, etc depending on land suitability and economic demand nationally or internationally.

I recommend you sweet sorghum (Sorghum bicolor). It's energy crop from Africa with high biomass and dry matter yield.Because sweet sorghum requires less water and has a higher fermentable sugar content than sugarcane, which contains more crystallizable sugars, it is better suited for ethanol production than sugarcane or other sources, and sweet sorghum ethanol is cleaner than sugarcane ethanol, when mixed with gasoline.

Regards

Dr Deka  raised a very good point ,  narrow genetic base of commercial crops in arid regions is perhaps the most pivotal towards lower productivity levels. Unfortunately , expanding aridity coupled  with increasing menace of soil salinity is adding further  fuel to the fire , with the result, challenges to sustain   crop production have multiplied by many dimensions. Abhishek  , you added some very pertinent links , worth reading all of them .

Thank you for your kind and quick suggestions

Hi Elfanah,

Best solution is to use reflective mirror bird scarers. This is a just a moving mirrors sparkle in the light, using the natural energy of breezes and the sun. Highly recommend :) 

In old days we had used cassette tapes over the field to give reflections (specially parrots, sparrows)  But now common practice is to use CD's 

article on this link may be useful

Hey Thiago Jose Florindo !

can you suggest some simple paper as I am doing cost analysis for the first time. and I am not from this background

Dear Anoop Kumar and All

If I understand your question my answer is this:

Soil starts as soon as the plant and animal life comes to live in the debris of the decomposition of a rock. On the death of these creatures, their material is incorporated into the soil, mixing with mineral substances. They then represent Soltner as "organic ingredients" or "organics"

Given the different types of organic matter (live, fresh, humic matter) that have multiple functions: processing, energy substrate, physical fertility. It follows a physicochemical fertility (mineral intake, therefore soil structure a long-term stability)

Dr Deka , so  far researches accrued on this issue , it is claimed bacteria of endophytic origin are more efficient compared to rhizophere origin , they are supposed to be metabolically more like a part of plant functioning . But , I wonder how to inoculate them ?. Shall we adopt soil inoculation or seed inoculation , very often seed inoculation finds difficulty in generating good plant response.

Dr Subba Rao, I too all the time think about this question raised by you, that how to take care about these interactions within a model, some of the approaches in model says that take the stress effect of the individual nutrient contributing the most stress, but that somehow is not convincing, for example if Zn is deficient even uptake efficiency of N is reduced, so many examples raised by you, we have to think together and bring some solution thanks for your valuable comments

regards