Crop yield data are critical for managing agricultural sustainability and assessing national food security. This study aims at increasing peanut productivity from its current levels by analyzing the yield gap (difference) of potential production between theoretical yield and actual farmers’ yields. The spatial yield gap of peanut for the Tiruvannamalai district of Tamil Nadu is examined in this investigation by integrating the products of microwave remote sensing (SAR Sentinel-1A) with the DSSAT CROPGRO Peanut simulation model. The CROPGRO (crop growth) Peanut model was calibrated and validated by conducting a field experiment at Oilseeds Research Station, Tindivanam during Rabi (spring) 2019 for predominant cultivars, i.e., TMV 7, TMV 13, VRI 2 and G 7. Actual attainable yield was recorded by organizing crop cutting experiments (CCEs) with the help of the Department of Agriculture Economics and Statistics in the respective monitoring villages. The regression analysis between the maximum recorded DSSAT leaf area index (LAI) at the peak flowering stage of peanut and the yield recorded by CCEs for the spatial yield estimation of peanut in the Tiruvannamalai district of Tamil Nadu during Rabi 2021 was carried out using ArcGIS 10.6 software. The DSSAT CROPGRO simulated potential yield ranged from 3194 to 4843 kg/ha, whereas actual yield ranged from 1228 to 3106 kg/ha, with a considerable disparity between the actual and potential yield levels (from 1217 to 2346 kg/ha) of the monitored locations. The minimum, maximum and average yield gaps in peanut for Tiruvannamalai district were assessed as 1890, 2324 and 2134 kg/ha, respectively. In order to reduce the production difference of peanut cultivation, farmers should focus more on management issues such as time of sowing, irrigation or water management, quantity and sources of nutrients, cultivar selection and availability of quality seeds tailored to each region.

Background: Groundnut, commonly known as peanut, is a significant oil, food and feed legume crop grown in all seasons in Tamil Nadu, including kharif, rabi and summer and it is cultivated both under irrigated and rainfed conditions in all the seasons at Thiruvannamlai district. One of the most important applications of remote sensing in agriculture is a Crop Acreage and Production Estimation (CAPE). The CAPE’s main goal is to estimate crop acreage and production of important crops, so that advanced food production, distribution and supply data were achieved. Methods: Multi-temporal Sentinel 1A SAR IW- GRD data with 20 m spatial resolution and 12 days temporal resolution of Vertical - Horizontal (V-H) polarization were downloaded for the period of 4th October 2020 to 8th January 2021 to have the full coverage during the crop growth period in the study area used for this work. Crop backscattering and multi-temporal features were extracted from MAPscape 5.2 automated pre-processing tool and its classified using supervised maximum likelihood classification for groundnut acreage extraction for Thiruvannamalai district. Result: The rabi groundnut area of Thiruvannamalai district of Tamil Nadu was estimated using SAR Sentinel-1A data as 32298 ha with a higher accuracy percentage of 87.4 and kappa coefficient of 0.75.

Rice cultivation in coastal river deltaic regions faces increasing challenges due to declining on-time river water availability, soil salinity and stagnating yields, which limit income growth for smallholder farmers. This study hypothesised that integrating water-saving irrigation, hydrogel application and intercropping could significantly improve aerobic rice performance and economic returns in coastal conditions. A field experiment was conducted during the summer season of 2022 at Karaikal, a coastal region in southern India, to assess the effects of two irrigation methods (drip irrigation and surface irrigation), two hydrogel levels (with and without application) and four intercropping systems (no intercrop, black gram, green gram and onion) on aerobic rice. The treatments were arranged in two separate two-factor randomised block designs under each irrigation method. The results showed that hydrogel application increased the grain yield of aerobic rice by 2.5 % from 4807 to 4923 kg ha-1. Surface irrigation produced 28 % higher yield of aerobic rice (5464 kg ha-1) than drip irrigation (4266 kg ha-1). The most profitable treatment was surface-irrigated aerobic rice intercropped with black gram and supplemented with hydrogel, which achieved the highest gross return (₹ 219450 ha-1), net return ( ₹ 162103 ha-1) and benefit-cost ratio (3.83). Here, we demonstrate that the strategic integration of surface irrigation, hydrogel application and legume intercropping can substantially improve rice yield and profitability under coastal conditions. This is the first study to evaluate such combined interventions for aerobic rice in the deltaic ecosystem of Karaikal. The findings offer a practical and scalable approach to enhance resource-use efficiency, income and sustainability in climate-vulnerable rice farming systems.

Crop yield data is critical for managing sustainable agriculture and assessing national food security. Current study aims to increase Peanut productivity from current levels by analyzing the yield gap of production potential between theoretical yield and actual farmers’ yields. The spatial yield gap of Peanut for Thiruvannamalai district of Tamil Nadu is examined in this paper by integrating the products of microwave remote sensing (SAR Sentinel-1A) with DSSAT CROPGRO peanut simulation model. CROPGRO Peanut model was calibrated and validated by conducting field experiment at Oilseeds Research Station, Tindivanam during Rabi 2019 for predominant cultivars viz. TMV 7, TMV 13, VRI 2 and G 7. Actual attainable yield was recorded by organizing CCE with help of Department of Agriculture Economics and Statistics in the respective monitoring Villages. Regression analysis between maximum recorded DSSAT Leaf Area Index (LAI) at peak flowering stage of peanut and yield recorded by Crop Cutting Experiment (CCE) for spatial yield estimation of Peanut in Thiruvannamalai district of Tamil Nadu during Rabi 2021 was carried out using ArcGIS 10.6 software. The results showed that the simulated potential yield ranged from 3194 to 4843 kg/ha, whereas actual yield ranged from 1228 to 3106 kg/ha, with a considerable disparity between the actual and potential yield levels (1217 to 2346 kg/ha) of the monitored locations. The minimum, maximum and average yield gaps in Peanut for Thiruvannamalai district was assessed as 1890, 2324 and 2134 kg/ha, respectively. To reduce the production difference (Yield gap) of Peanut cultivation, farmers should focus more on management issues such as time of sowing, irrigation or water management, quantity and sources of nutrients, cultivar selection and availability of quality seeds tailored to each region.

Black gram is an important legume crop cultivated throughout the world for its protein content and economic importance. The integrated nutrient management practice is the key strategy to increase the production and productivity of black gram to meet the protein needs of the growing population. There is an immediate need for organic manure application along with inorganic fertilizer for increasing the nutrient uptake efficiency of crops. The goal of the field experiment was to maximise the delivery of nutrients by recycling residue from the cropping system's related components. Different organic manures and the appropriate dosages of NPK fertilisers were used in the studies from 2019 to 2021 and the field was laid out in split plot statistical design with 5 main plots viz., M1, M2, M3, M4, M5 and 3 Sub plots were fixed with different fertilizer levels viz., S1, S2 and S3. The significant influences on growth and yield attributes of black gram were observed. Nitrogen, phosphorus and potassium content and uptake in grain and haulm yield significantly increased with the application of M2S1 compared to other combinations tried in both years. This experiment highlights the effectiveness of integrated nutrient management (INM) using organic manure and inorganic fertilizers. This approach can improve crop yield while promoting sustainability by reducing reliance solely on chemical fertilizers.

Afield experiment was conducted at wetland farm of Tamil Nadu Agricultural University, Coimbatore during kharif 2017 to study the influence of different rice establishment methods on yield, labour productivity, economic water productivity and energetics in CO (R) 51. The experiment was carried out with five transplanting and four direct sown methods of establishment. The results revealed that crop established through square planting (SRI) with single seedling recorded significantly higher grain yield (6860 kg/ha), straw yield (10195 kg/ha), total output energy (228092 MJ), net energy gain (210452 MJ) and energy use efficiency (12.9%) compared to other establishment methods. Among the different rice establishment methods labour productivity (2.38) and economic water productivity (Rs 93.8/ha mm) were registered higher in drum seeding method under pudddled condition.