James John Camberato

• Ph.D.
• Professor (Full) at Purdue University West Lafayette

Phosphorus (P) is critical for maximizing agricultural production and represents an appreciable input cost. Geologic sources of P that are most easily mined are a finite resource, while P transported from agricultural land to surface waters contributes to water quality degradation. Improved knowledge of P timing needs by corn (maize) can help infor...

Indiana cultivates approximately 7000 acres of watermelons ( Citrullus lanatus ) every year, with the majority of production concentrated in southern Indiana, thus making this region a key area for watermelon production in the United States. Diverse irrigation and fertilization practices are used for watermelon production in the region, yet their e...

Quantifying root length, surface area, average diameter, and volume of fully‐matured corn (Zea mays L.) is labor intensive, time consuming, and costly. Accurate and efficient subsampling techniques are needed to overcome these limitations. In this study, eight corn root systems were grown to maturity in a sand‐culture hydroponics system to develop...

Closed depressions are common landscape features across glaciated landscapes. Erosion and runoff from depression hillslopes may result in phosphorus (P) accumulation near the bottom of the depression, with this “legacy P” potentially at risk of loss to surface waters when drained via tile drainage. We assessed spatial patterns of soil P within a ti...

The occurrence of S deficiency in Midwest crops in the past 20 years is likely a result of the consistent decline of atmospheric S deposition during this time period. In the absence of intentional S fertilization, crops utilize SO4‐S mineralized from soil organic matter and potentially the incidental application of S in non‐S fertilizers. Based on...

Plant N concentration (PNC) has been commonly used to guide farmers in assessing maize (Zea mays L.) N status and making in-season N fertilization decisions. However, PNC varies based on the development stage. Therefore, a relationship between biomass and N concentration is needed (i.e., critical N dilution curve; CNDC) to better understand when pl...

Plant N concentration (PNC) has been commonly used to guide farmers in assessing maize (Zea mays L.) N status and making in-season N fertilization decisions. However, PNC varies based on the development stage and therefore a relationship between biomass and N concentration is needed (i.e., critical N dilution curves; CNDC) to better understand when...

Improving corn (Zea mays L.) nitrogen (N) rate fertilizer recommendation tools can improve farmers’ profits and mitigate N pollution. Numerous approaches have been tested to improve these tools, but to date improvements for predicting economically optimum N rate (EONR) have been modest. This work's objective was to use ensemble learning to improve...

Purpose Farmers need alternative approaches to manage nitrogen (N) that meet crop needs while reducing loss to the environment. Identifying crop genotypes that promote decomposition of organic materials and understanding the potential mechanisms responsible could help address this challenge. Consequently, we aimed to 1) determine whether carrot gen...

Beginning abruptly in the second half of the Spring 2020 semester at Purdue University, we modified our teaching approach in Introductory Soil Science and Forest Soils courses (AGRY 255/270) with a combined annual enrollment of ∼370 students to cope with the COVID‐19 pandemic. In that semester, we went to entirely virtual lecture, lab, and discussi...

In general, remote sensing studies assessing cover crop growth are species nonspecific, use imagery from satellites or modified unmanned aerial vehicles (UAVs), and rely on multispectral vegetation indexes (VIs). However, using RGB imagery and visible-spectrum VIs from commercial off-the-shelf (COTS) UAVs to assess species specific cover crop growt...

Previous studies have shown that excess phosphorus (P) uptake by maize can lead to a decreased grain yield. Part one of this study demonstrated that maize experienced luxury consumption of P in three phases of P uptake. The objective of this work was to further explore how P uptake indirectly impacts the uptake of other nutrients and their transloc...

Development of a more precise and process-based tool for making phosphorus (P) recommendations requires detailed understanding of plant P uptake needs. Future adaptation of a nutrient uptake model for this purpose must utilize a mass-balance approach. The objectives of this study were to determine the minimum P uptake mass required for achieving ma...

Cereal rye (Secale cereale) is widely adopted as a cover crop in the Midwest, USA, because of its nitrogen (N) scavenging ability. However, there is a dearth of knowledge regarding cereal rye N fate and utilization by the subsequent corn or soybean crop. Thus, the objectives of this study were to (i) Investigate the uptake of newly applied spring N...

Cereal rye (Secale cereale L.; CR) is promoted as a cover crop as a practice for reducing nitrate leaching losses in the U.S. Midwest. However, early‐season nitrogen immobilization during CR decomposition may contribute to yield reductions in corn (Zea mays L.). Field trials were conducted at three sites to determine if N as a starter fertilizer co...

Purpose Farmers need alternative approaches to manage nitrogen (N) that meet crop needs while reducing loss to the environment. Identifying crop genotypes that promote positive priming of organic matter in soil could help address this challenge. We aimed to 1) determine whether carrot genotypes differ in their potential to facilitate organic matter...

Cereal rye (CR, Secale cereale, L.) is the most common cover crop species in the United States. However, despite numerous environmental benefits, the number of acres planted to CR annually remains low. Lack of adoption could be related to the dearth of knowledge on the fate of scavenged CR nitrogen. Thus, the objectives of this study were to use ¹⁵...

Subsurface drainage modifications are a common practice in agricultural watersheds, especially in poorly drained soils of the American Midwest, yet our understanding of their impact on baseflow generation processes is incomplete. By extension, these same practices can make baseflow vulnerable to salinization. To address these knowledge gaps, a comb...

Accurate nitrogen (N) diagnosis early in the growing season across diverse soil, weather, and management conditions is challenging. Strategies using multi-source data are hypothesized to perform significantly better than approaches using crop sensing information alone. The objective of this study was to evaluate, across diverse environments, the po...

Soil phosphorus (P) solubility and kinetics partly control dissolved P losses to surface water and uptake by plants. While previous studies have focused on batch techniques for measuring soil P desorption kinetics, flow-through techniques are more realistic because they simulate P removal from the system, akin to runoff, leaching, and plant uptake....

Nitrogen fertilizer recommendations in corn (Zea mays L.) that match the economically optimal nitrogen fertilizer rate (EONR) are imperative for profitability and minimizing environmental degradation. However, the amount of soil N available for the crop depends on soil and weather factors, making it difficult to know the EONR from year‐to‐year and...

There are unique advantages and disadvantages to using the field, greenhouse, growth chamber, and media-less techniques for growing maize (Zea mays L.) for research purposes. Soil-buffered nutrients such as phosphorus (P) do not allow for precise control of solution concentrations in the field, while greenhouses, growth chambers, and hydroponics pr...

Improving corn (Zeamays L.) N managementis pertinent to economic andenvironmental objectives. However, there are limited comprehensive data sources to develop and test N fertilizer decision aid tools across a wide geographic range of soil and weather scenarios. Therefore, a public‐industry partnership was formed to conduct standardized corn N rate...

Improving corn (Zea mays L.) N fertilizer rate recommendation tools is necessary for improving farmers’ profits and minimizing N pollution. Research has repeatedly shown that weather and soil factors influence available N and crop N need. Adjusting available corn N recommendation tools with soil and weather measurements could improve farmers’ abili...

Splitting the N application into two or more timings may improve corn (Zea mays L.) grain yield and N recovery relative to a single‐N application. A 49 site‐year study across eight U.S. Midwestern states compared the effect of an at‐planting (single‐N application) and two split‐N applications [45 (45+SD) or 90 kg N ha⁻¹ (90+SD) at planting with the...

Anaerobic potentially mineralizable nitrogen (PMN) combined with preplant nitrate test (PPNT) or pre‐sidedress nitrate test (PSNT) may improve corn (Zea mays L.) N management. Forty‐nine corn N response studies were conducted across the U.S. Midwest to evaluate the capacity of PPNT and PSNT to predict grain yield, N uptake, and economic optimal N r...

Soil microbes drive biological functions that mediate chemical and physical processes necessary for plants to sustain growth. Laboratory soil respiration has been proposed as one universal soil health indicator representing these functions, potentially informing crop and soil management decisions. Research is needed to test the premise that soil re...

The anaerobic potentially mineralizable N (PMN) test combined with the preplant (PPNT) and presidedress (PSNT) nitrate tests may improve corn (Zea mays L.) N fertilization predictions. Forty‐nine corn N response experiments (mostly corn following soybean [Glycine max (L.) Merr.]) were conducted in the U.S. Midwest from 2014–2016 to evaluate the abi...

Understanding the variables that affect the anaerobic potentially mineralizable N (PMNan) test should lead to a standard procedure of sample collection and incubation length, improving PMNan as a tool in corn (Zea mays L.) N management. We evaluated the effect of soil sample timing (preplant and V5 corn development stage [V5]), N fertilization (0 a...

Sub-Saharan Africa is facing food security challenges due, in part, to decades of soil nitrogen (N) depletion. Applying N fertilizer could increase crop yields and replenish soil N pools. From 2010 to 2015, field experiments conducted in Embu and Kiboko, Kenya and Harare, Zimbabwe investigated yield and N uptake response of six maize (Zea mays L.)...

Determining which corn (Zea mays L.) N fertilizer rate recommendation tools best predict crop N need would be valuable for maximizing profits and minimizing environmental consequences. Simultaneous comparisons of multiple tools across various environmental conditions have been limited. The objectives of this research were to evaluate the performanc...

In pursuit of maximum grain yield farmers in the North China Plain usually apply excessive N fertilizer, resulting in wasted resources and environmental pollution. To assess the economic and environmental performances of different nitrogen rates will be conductive to sustain cleaner crop production. An 8-year field experiment was carried out with f...

Low fertilizer application rates for several decades have depleted soil nutrients in Sub-Saharan Africa (SSA) and contributed to relatively stagnant maize (Zea mays L.) yields. As maize is a staple crop, nutrient depletion has resulted in major food insecurity. While one potential solution is to apply more nitrogen (N) fertilizer, previous studies...

Estimates of mineralizable N with the anaerobic potentially mineralizable N (PMNan) test could improve predictions of corn (Zea mays L.) economic optimal N rate (EONR). A study across eight US midwestern states was conducted to quantify the predictability of EONR for single and split N applications by PMNan. Treatment factors included different soi...

Nitrogen provided to crops through mineralization is an important factor in N management guidelines. Understanding of the interactive effects of soil and weather conditions on N mineralization needs to be improved. Relationships between anaerobic potentially mineralizable N (PMNan) and soil and weather conditions were evaluated under the contrastin...

The study was designed to investigate nitrogen and carbon contents, nitrogen use efficiency, and antioxidants of a tolerant accession PI231578 (TOL) and a susceptible PI306292 (SUS) of perennial ryegrass subjected to 7.5 mM N (control) and 0.75 mM N (low) for 6, 12, and 20 d in a growth chamber. The SUS had decreased plant height, dry matter, shoot...

Nitrogen (N) fertilizer recommendation tools could be improved for estimating corn (Zea mays L.) N needs by incorporating site-specific soil and weather information. However, an evaluation of analytical methods is needed to determine the success of incorporating this information. The objectives of this research were to evaluate statistical and mach...

Plant growth regulators (PGRs) can mediate plant response to salinity stress. Perennial ryegrass ( Lolium perenne ) cultivars of BrightStar SLT, Catalina, Inspire, and SR4660ST were exposed to 0, 100, or 200 m m NaCl for 14 d. 6-benzyladenine (6-BA, 10 µ m ), γ-aminobutyric acid (GABA, 500 µ m ), nitric oxide (NO, 200 µ m ), and H 2 O were applied...

Occasionally, the classic understanding of the effect of pH on P uptake from soils is questioned through the claim that maximum P uptake occurs at a pH much lower than 6.5–7. The purpose of this paper was to thoroughly examine that claim and provide a critical review on soil processes that control how soil pH affects P solubility and availability....

Core Ideas Canopy sensor performance improved using site‐specific information. Evenness of early‐season rainfall is crucial for adjusting N recommendations. Adjusting N recommendations using measured vs. USDA mapped soil data performed alike Active‐optical reflectance sensors (AORS) use light reflectance characteristics from a crop canopy as an in...

Core Ideas A Machine Learning approach was innovatively used to predict corn EONR. Two features were created to approximate hydrological conditions for modeling EONR. Soil hydrology conditions were found essential in successful modeling in‐season EONR. Determination of in‐season N requirement for corn ( Zea mays L.) is challenging due to interacti...

Core Ideas Active‐optical reflectance sensor algorithms perform poorly outside the area for which they were originally developed. The red edge waveband is more sensitive to N stress than the red waveband. Some active‐optical reflectance algorithms are dependent on the sensor for which they were developed. Uncertainty exists with corn ( Zea mays L....

To clarify how the components of the entire photosynthetic electron transport chain in response to drought stress in maize. The activities of photosystem II (PSII), photosystem I (PSI), and the electron transport chain between PSII and PSI of maize were investigated by prompt fluorescence (PF), delayed fluorescence (DF) and 820 nm modulated reflect...

Use and development of soil biological tests for estimating soil nitrogen (N) availability and subsequently corn (Zea mays L.) fertilizer N recommendations is garnering considerable interest.The objective of this research was to evaluate relationships between the Haney Soil Health Test (HSHT), also known as the Soil Health Tool or Haney test, and t...

Mehlich-3 (M3) is one of the most common agronomic and environmental phosphorus (P) extractants for determining P fertilizer requirements and the potential for non-point source pollution. Understanding how soil properties impact M3 extractability can improve our ability to properly use this soil test. The objectives of this study were to investigat...

Core Ideas Nitrogen recommendations for individual corn fields are less accurate than desired. Nitrogen recommendations need improvement for economic and environmental reasons. A review of fundamental concepts will improve understanding about N recommendations. Examination of N recommendation systems, tests, and models will improve recommendations....

This is a paper that compares the effect of single near planting nitrogen fertilizer applications and splitting up the nitrogen fertilizer application on soil nitrate-nitrogen content and corn grain yield

Core Ideas Late‐split N applications at V12 increased total N uptake and N recovery efficiency. Gains in N recovery with late‐split N came from increased post‐silking N uptake. Increased whole‐plant N accumulation by R6 did not result in increased grain yields. Grain yield was not sensitive to in‐season N timing in this single‐location study. Newer...

Large patch (LP), caused by Rhizoctonia solani Kühn AG 2‐2 ‘LP’, is an important disease of seashore paspalum ( Paspalum vaginatum Sw.) in South Carolina. Two research putting greens were planted in 2005 at Clemson University Pee Dee Research and Education Center (PDREC) in Florence, SC, and at May River Golf Club (MRGC), Bluffton, SC to cultivars...

Core Ideas The geographic scope, scale, and unique collaborative arrangement warrant documenting details of this work. The purpose of this article is to describe how the research was undertaken, reasons for the research methods, and the project's potential value. The project generated a valuable dataset across a wide array of weather and soils that...

Highlights This work utilizes “multi-stage pulse labeling” ¹⁵N applications, primarily during reproductive growth stages, as a phenotyping strategy to identify maize hybrids with superior N use efficiency (NUE) under low N conditions. Research using labeled isotopic N (¹⁵N) can precisely quantify fertilizer nitrogen (N) uptake and organ-specific N...

We review the evidence for a naturally occurring acid sulfate weathering event along the southern shore of Lake Michigan that was initiated ~ 15,000 years BP (before present) at the close of the Wisconsin Glaciation. The evidence includes: (1) “unproductive black soils” that were encountered when settlers drained the wetlands in the area for agricu...

Hybrid era and management practices like nitrogen (N) rate and plant density influence canopy traits and their correlations with grain yield, kernel number, and kernel weight in maize (Zea mays L.). A four site-year study was conducted employing two N rates (55 and 220 kg N ha⁻¹) with three plant densities between 54,000 and 104,000 plants ha⁻¹ for...

Diplodia ear rot (DER), caused by the fungus Stenocarpella maydis, has become a prevalent corn disease in the Midwest. The survival of S. maydis on corn kernels and stalks was evaluated in Tippecanoe, Co., Indiana, over 17 months. Infested corn residue was either left on the soil surface or buried at 10 or 20 cm. Survival of S. maydis was determine...

Sub-Saharan Africa suffers from low soil fertility and poor grain yields creating a food security crisis for its growing population. One proposal to address fertilizer cost problems and food security requirements is the use of hybrids with enhanced nitrogen‐use‐efficiency (NUE), which has the potential to increase the maize yield substantially. Dir...

This paper evaluates the use of the anaerobic potentially mineralizable nitrogen test as an index for nitrogen mineralization and its use to estimate N fertilizer needs of corn.

Research attention to improving source and sink strength in maize production is requisite for enhancing yield. Improvement in source strength has been achieved with higher post-silking dry matter accumulation, whereas historical improvement in sink strength has been mostly attributed to increasing kernel number (KN) per unit area, in part because K...

A field experiment was conducted to study the effects of shading on the photosynthetic characteristics and mesophyll cell ultrastructure of two summer maize hybrids Denghai605 (DH605) and Zhengdan958 (ZD958). The ambient sunlight treatment was used as control (CK) and shading treatments (40 % of ambient sunlight) were applied at different growth st...

Maintaining photosynthetic activities is a critical function that allows crops to adapt to drought stress. We evaluated drought-induced changes in photosynthetic performance via gas exchange as well as photosynthetic electron transport and carbon assimilation process in two maize (Zea mays L.) cvs. Shaandan 609 (SD609) and Zhengdan 958 (ZD958). Pla...

Current guidance and equipment technologies permit anhydrous ammonia (NH3) to be confidently placed parallel to crop rows in both before- and after-planting situations at shallower depths than traditional applications. Field studies from 2010 to 2012 investigated the effects of pre-plant vs. side-dress NH3 at four N rates (0, 90, 145, and 202 kg N...

A summary of multiple years of field-scale research on the yield response of corn to plant population in Indiana.

A field experiment was conducted to study the effects of shading on tassel and ear development and yield formation of three summer maize hybrids Zhenjie 2 (ZJ2), Denghai 605 (DH605), and Zhengdan 958 (ZD958). The ambient sunlight treatment was used as control (CK) and shading treatments (40 % of ambient sunlight) were applied at different growth st...

Efforts have been made in numerous studies to better understand N dynamics to increase corn yields and N efficiency, but most often it is not possible to separate the uptake of indigenous soil- versus fertilizer-derived N over time. The approach of using a “pulse-labeled N” technique provides potentially more accurate information about the fate of...

mprovement in corn productivity as well as resource efficiency depends, in part, on acquiring new knowledge concerning physiological pathways and timeframes with respect to plant nitrogen (N) allocation and efficiencies. Hence, this present study examined the coinciding partitioning of biomass and N in plant components at several corn growth stages...

Chemical plant growth regulators (PGRs) are important tools in greenhouse ornamental crop production because growers must increasingly meet specifications for plant shipping and marketability. However, the role of water quality parameters such as pH or alkalinity (bicarbonate in this study) on final PGR solution pH is not well documented and could...

Combining herbicide-resistant and Bt traits in corn (Zea mays L.) hybrids may impact insect resistance management due to volunteer corn. Some Bt toxins may be expressed at lower levels by N deficient corn roots. Corn plants with sub-lethal levels of Bt expression could accelerate the evolution of Bt resistance in target insects. Our objective was t...

With the advent of precision guidance systems, maize (Zea mays L.) farmers in various tillage systems have more options in pre-plant nutrient banding relative to the intended crop rows. Anhydrous ammonia (NH3) placement during pre-plant application is of interest because of concerns for possible ammonia toxicity to maize seedlings when high NH3 rat...

It is important for cost, resource efficiency, and environmental reasons to improve nitrogen use efficiency (NUE), understood here to mean the change in grain yield per unit of N fertilizer applied relative to the control (i.e. zero N). Major research efforts are underway at genetic, physiology, and management levels in companies and public researc...

Improved plant N utilization and partitioning is critical for future improvements in maize (Zea mays L.) grain yield (GY). The overall research objective was to gain understanding of the physiological mechanisms underpinning biomass (BM), N uptake partitioning, and GY processes during the reproductive period for two maize hybrids grown at varying p...

Salinity stress inhibits plant growth and development. The objectives of this study were to investigate growth response, carbohydrate and ion accumulation of diverse perennial ryegrass (Lolium perenne L.) accessions under salinity stress and to determine phenotypic traits associated with variability in salinity tolerance. Ten diverse accessions of...

Four complete water-soluble fertilizer (WSF) formulations including micronutrients applied at 200 mg·L-1 nitrogen (N) at each irrigation [Peters Excel (21N-2.2P-16.5K), Daniels (10N-1.8P-2.5K), Peters Professional (15N-1.3P-20.8K), and Jack's Professional (20N-1.3P-15.7K)] were compared with two controlled-release fertilizer (CRF) products (also co...

Natural variation in salinity response, effects of population structure on growth and physiological traits and gene-trait association were examined in 56 global collections of diverse perennial ryegrass (Lolium perenne L.) accessions. Three population structure groups were identified with 66 simple sequence repeat markers, which on average accounte...

Understanding nutrient balances in changing cropping systems is critical to appropriately adjust agronomic recommendations and inform breeding efforts to increase nutrient efficiencies. Research to determine the season-long phosphorus (P), potassium (K) and sulfur (S) uptake and partitioning dynamics of maize (Zea mays L.) as affected by low, mediu...

Volunteer corn expressing herbicide resistance is a problematic weed. This issue is partially due to the increasing prevalence of stacking both herbicide and insect-resistant (mainly Bt) traits into the same genetically-modified plant. Previous research indicates that the Bt toxin concentrations in nitrogen deficient volunteer corn roots may be les...

INSTINCT or N-SERVE with Band-Injected UAN: Does it Matter? B. MENELAS, B. C. Joern and J. J. Camberato. Department of Agronomy, Purdue University. West Lafayette, IN 47907. Instinct is a microencapsulated formulation of nitrapyrin designed to reduce N loss from urea-ammonium nitrate (UAN) and liquid manure. However, N-Serve is an unencapsulated...

Our study examined the effect that decision-maker risk preferences have on nitrogen application rate decisions to corn in Indiana. Previous research suggests that uncertainty increases the rate at which farmers apply nitrogen fertilizer. With increased volatility that has arisen in crop and input prices since the Energy Policy Act of 2005, it is im...

Volunteer corn (VC) in hybrid corn has become more prevalent in recent years and can reduce grain yield. Nitrogen (N) management can influence VC interference in corn. Field experiments were established to determine the effects of N fertilizer management and VC interference on hybrid corn growth and grain yield. Treatments consisted of three VC den...

The North American native plants Spiraea alba and S. tomentosa have potential as landscape plants because they are small- to medium-sized shrubs with showy flowers that persist from early to late summer. However, the cultural requirements of these species are not well documented. Both species grow in slightly acidic soils in their native habitats....

Rapid adoption of glyphosate-resistant (GR) corn hybrids has led to the reemergence of volunteer corn as a problematic weed in soybean and has made controlling the initial stand of corn in a replant situation more difficult. If volunteer corn in soybean or the initial corn stand in a replant situation is not controlled, yield loss can occur. Cletho...

Maize breeding programs develop many thousands of new hybrids each year that must be tested for performance against existing varieties. The yield potential of a maize variety depends on soil and weather conditions during crop growth and development. One key factor in selecting new cultivars involves an assessment of the stability of hybrid performa...

Site-specific management of soil fertility has been based on soil sampling in grid patterns or within soil mapping Units Without taking full advantage of terrain-soil relationships. The goal of this study was to determine whether terrain attributes relate significantly to soil K availability. The topographic wetness index (TWI), a terrain attribute...

Watermelon, Citrullus lanatus (Thunb.) Matsum. & Nakai, crops are continuously exposed to soilborne diseases. In many areas of the United States, greenhouse-raised watermelon seedlings are transplanted to the field to allow for early crop establishment and early fruit production. This practice can result in weakened root systems, which potentially...

Plant diseases are mostly controlled by chemical pesticides and in some cases by cultural practices. However, the widespread use of chemicals in agriculture has been a subject of public concern and scrutiny due to the potential harmful effects on the environment, their undesirable effects on nontarget organisms, and possible carcinogenicity of some...

W. L. 2006. Pulp and paper mill by-products as soil amendments and plant nutrient sources. Can. J. Soil Sci. 86: 641–653. Pulp and paper mill sludges are produced from primary and secondary treatment of wastes derived from virgin wood fiber sources, recycled paper products, and non-wood fibers. Sludges and sludge composts may be utilized in agricul...