J. S. Sudha Rani’s scientific contributions

Farmers can employ the water-saving technique known as alternate wetting and drying (AWD) to reduce the irrigation water used in rice fields while maintaining crop yields. This irrigation method decreases water usage in rice cultivation by allowing periods of unsaturated soil during the growing season without compromising productivity. During the Kharif seasons of 2018 and 2019, 15 frontline demonstrations were conducted on farmers' fields. This advanced technique resulted in grain yields averaging 4.5% higher (6031 kg/ha) compared to traditional methods (5772 kg/ha). It also led to increased net returns (Rs. 55,552/-) and gross returns (Rs. 102,819/-). Using the AWD method, a B:C ratio of 2.2 was achieved, saving Rs. 1,900/-per hectare compared to traditional practices (GR: 98,585/-, NR: 49,437/-, B:C 1.9). Introduction Food security is increasingly becoming a critical concern as natural resources, such as land and water, are depleting while global food consumption rises due to population growth (Li, H., and Li, M., 2010; Lampayan et al., 2015a) [7, 5]. Recent projections indicate severe water shortages in the coming decades. To conserve water and other inputs, an alternative rice cultivation system must be developed. By allowing periods of non-submerged conditions for several days during the growth season, water inputs can be minimized, and water productivity increased unless fissures appear through the plough sole (Belder et al., 2004) [9]. Farmers can adopt the water-saving technique known as Alternate Wetting and Drying (AWD) to reduce irrigation water use in rice fields without compromising yields (Lampayan et al., 2015b) [6]. This method lowers water usage in rice cultivation by introducing unsaturated soil conditions during the growth season. According to Suresh Kulkarni (2011) [2] , using a field water tube in AWD is safe if water use is limited to 25%. Tuong (2007) [3] documented the successful use of field water tubes in AWD management to monitor water depth, indicate the optimal time for irrigation, and save water without affecting yields. The aim of the current front-line demonstrations was to highlight the benefits of the AWD technique in rice production to farmers in the Rangareddy, Vikarabad, and Medchal districts of Telangana State, India. Addressing climate change in rice production requires a climate-smart strategy that provides advantages for both adaptation and mitigation.

A field study was taken up to evaluate the influence of organic sources of nutrients and inorganic fertility levels in aerobic rice during kharif 2017 and kharif 2018 at Indian Institute of Rice Research, Rajendra Nagar, Hyderabad, Telangana. The experiment was laid out in split plot design with three replications. The treatment comprised of M1: Neem leaf manure 6 t ha-1; M2: Vermicompost 2 t ha-1; M3: Goat manure 5 t ha-1; M4: Microbial consortia [seed treatment 4g kg-1 + soil application 4 kg ha-1]. The sub-plot treatments comprised of S1: Control; S2: 50 % RDF; S3: 75 % RDF; S4: 100 % RDF [Recommended Dose of Fertilizer 120:60:40 kg ha-1]. It was observed that, nutrient uptake by aerobic rice was significantly influenced with application of organic nutrient sources and inorganic nutrient levels. N, P and K uptakes by rice were higher with vermicompost @ 2 t ha-1 or goat manure @ 5 t ha-1 among organic sources and 100% RDF among nutrient levels. Vermicompost recorded significantly highest nitrogen (55.76, 71.7, 91.6 and 103.5 kg ha-1 respectively), phosphorus (9.04, 15.4, 18.0 and 20.5 kg ha-1) and potassium (39.7, 60.0, 76.3, 107.1 kg ha-1) uptake by rice crop at MT, PI, 50% FL and harvest and it was found at par with goat manure ( viz; nitrogen : 50.79, 66.1, 85.6 and 97.7 kg ha-1 ; phosphorus : 8.33, 14.11, 16.4 and 19.2 kg ha-1 and potassium : 38.2, 59.5, 75.2 and 84.0 kg ha-1 at MT, PI, 50% FL and harvest ) while the lowest nutrient uptake (viz; nitrogen: 37.86, 46.1, 60.9 and 77.3 kg ha-1, phosphorus: 5.74, 8.59, 11.4 and 12.6 kg ha-1 and potassium: 25.8, 41.3, 48.6 and 71.5 kg ha-1) was found with application neem leaf manure. Application of 100% RDF significantly increased N (63.58, 80.0, 99.1 and 123.1 kg ha-1), P (9.90, 17.1, 19.9 and 24.3 kg ha-1) and K (47.3, 70.8, 88.9 and 119.5 kg ha-1) and the lowest N (26.37, 32.5, 45.6 and 47.0 kg ha-1), P (4.11, 6.12, 7.7 & 7.8 kg ha-1) and K (19.3, 28.3, 34.7 and 56.7 kg ha-1) was recorded with control. Conjunctive use of 75% of RDF along with vermicompost (M2S3) or goat manure (M3S3) resulted in statistically on par nitrogen and phosphorus uptake with that of 100% RDF and the lowest nitrogen and phosphorus uptake were recorded with combination of either neem leaf manure or microbial consortia and no application of fertilizer (M1S1 and M4S1, respectively).

Continuous growing of rice –rice mono-cropping over the years and excessive dependence on chemical fertilizers alone has led to decrease in soil fertility and productivity. Rice–maize double cropping is gaining popularity in many Asian countries including India. fertilizer need of a crop in a system is strongly influenced by the preceding crops and the amount of fertilizers applied to them. Cropping with two nutrient intensive cereals like rice-maize would remove a substantial quantity of plant nutrients from soil during continued agriculture round the year, envisaging the need for adoption of efficient nutrient management practices for sustained soil health and improving system productivity. A field experimentt was carried out to study the residual effect of organic nutrient sources and inorganic fertilizer levels on yield attributes and yield of zero till maize. The experiment was laid out in split plot design with four organic sources of nutrients applied to preceding rice as main plots viz: M1: Neem leaf manure @ 6 t ha-1; M2: Vermicompost @ 2 t ha-1; M3: Goat manure @ 5 t ha-1; M4: Microbial consortia [seed treatment @ 4 g kg-1 + soil application @ 4 kg ha-1] and four subplots with graded doses of fertilizers viz: S1: Control; S2: 50% RDF; S3: 75% RDF and S4: 100% RDF (180:60:60). The study revealed that various organic nutrient sources and graded fertilizer doses exerted a remarkable effect on plant height, LAI, dry matter production and Days to 50% silking which resulted in significantly higher grain, stover yield and harvest index of zero till maize.