ICAR-Indian Agricultural Research Institute Research Articles

Unraveling the physiological and molecular mechanisms regulating grain yield under combined drought and heat stress in wheat (Triticum aestivum)

An experiment was conducted during winter (rabi) seasons of 2020–21 and 2021–22 at the research farm of ICAR-Indian Agricultural Research Institute, New Delhi to assess the impacts of heat and drought stresses, both individually and combined, on wheat (Triticum aestivum L.) plants during the reproductive stage. Four wheat genotypes (C306, HD2967, Raj3765 and WL711) were subjected to heat stress (H), drought stress (D) and combined heat, and drought stress (HD) conditions at the anthesis stage. The research investigated various physiological, biochemical and grain yield parameters, as well as the relative expression of genes involved in the proline and abscisic acid (ABA) metabolic pathways. Among the tested genotypes, Raj3765 exhibited decreased ABA levels and increased proline accumulation during the anthesis stage under both individual and combined stress conditions. Notably, Raj3765 also displayed highergrain yield compared to the other 3 genotypes under all stress conditions, indicating that elevated proline levels and reduced ABA levels likely contributed to its resilience. Furthermore, the study revealed that the combination of heat and drought stresses had a more severe detrimental effect on wheat plants compared to individual stress treatments. These findings underscore the significance of comprehensively studying combined stress conditions, as they can result in substantial yield losses in wheat crop development and productivity.

Genotypic differences in root architecture and physiological characteristics in mango (Mangifera indica) under drought

An experiment was conducted at the research farm of ICAR-Indian Agricultural Research Institute, New Delhi during 2020 and 2021 to study the genotypic differences in root architecture and physiological characteristics in mango (Mangifera indica L.) under drought. One-year-old polyembryonic 7 mango rootstock genotypes were exposed to normal irrigation and drought conditions for 24 days. The drought-induced increased total plant weight and dry weight in Kurukkan. The shoot dry weight decreased in all genotypes ranging from 5.13% in OLP-Z-6/1 to 81.82% in Kurukkan. There was a lesser reduction in membrane stability index in Kurukkan and K-5, stomata count in Kurukkan, Olour and OPK-3-7/12 at the end of the drought period. Root surface area increased under drought in Kurukkan, while it decreased more in K-5. Correlation studies confirmed a strong positive relationship between relative water content (RWC) and membrane stability index (MSI), number of stomata (SC), number of leaves (NL), root tips (RT) and root forks (NRF); MSI and number of root tips (NRT); dry weight of the whole plant and root surface area (RSA); the dry weight of roots and root volume (RV), RSA, and plant height (Ph); root length (RL) and RSA, RT, and NRF. Kurukkan was identified as drought-tolerant based on a higher SC, RWC, RV, RSA, dry mass, NRT and NRF. Results indicated that the root indices offer a promising strategy for the screening of drought-tolerant mango genotypes.

Assessing the Impact of Altered Clay Mineral and Red Mud Derivatives on the Characteristics of Mustard (B. juncea) and the Soil Arsenic Content

A pot experiment was conducted during the winter season (rabi) of 2020-21 at ICAR-Indian Agricultural Research Institute, New Delhi. Indian mustard (Brassica juncea) was cultivated to investigate the impact of modified clay mineral (Bentonite) and Red mud on yield characteristics and total arsenic content in the soil. The main objective was to examine how the application of modified clay mineral and red mud (Fe-exchanged bentonite, Dimethyl sulfoxide-intercalated bentonite, and Iron-exchanged red mud) would affect the yield attributes of Indian mustard. The initial soil's total arsenic content was 16.2 mg kg-1. The results revealed that all the mentioned treatments led to a significant increase in leaf biomass and root volume compared to the control pot. Significantly, highest leaf biomass (g pot-1) was recorded in Fe-exchanged bentonite (4.10 g pot-1) followed by Dimethyl sulfoxide-intercalated bentonite (4.00 g pot-1), and Iron-exchanged redmud (3.93 g pot-1) respectively at the rate of 5.00 g product per kg soil. The highest root volume (6.6 cm2) was observed in soil treated with 5.00 g kg-1 of Fe-exchanged bentonite. Dimethyl sulfoxide-intercalated bentonite, and Iron-exchanged red mud also showed positive effects but to a lesser extent. total As content in contaminated soil was thoroughly investigated, and the results revealed that these clays did not exert a significant influence on the total As content under the given application rates.

Morphological characterization and molecular validation for ToLCV resistance (Ty-2 and Ty-3 genes) in tomato (Solanum lycopersicum)

An experiment was conducted during the rainy (kharif) season of 2019 and 2020 at ICAR-Indian Agricultural Research Institute, New Delhi to identify the potential genotypes having good horticultural traits along with strong and durable resistance against ToLCV disease of tomato (Solanum lycopersicum L.). A diverse set of 30 tomato genotypes carrying different Ty genes were screened out at phenotypic and genotypic level. First appearance/symptom of tomato leaf curl virus (ToLCV) disease was recorded in Pusa 120 only after 16 days of transplanting (DAT). Within 30 days of transplanting most of the genotypes, viz. Pusa 120, DT12, DT16, DT6 and Pusa Sheetal recorded 80 to 100 PDI (per cent disease incidence) and they were rated as highly susceptible to ToLCV. While at 90 DAT ToLCVincidence (≤15%) was observed in DT2, DT8, DT17, DT20 and DT30 and were categorized a resistant. None of the genotype was found as highly resistant. Four genotypes, viz. DT2, DT10, DT20 and DT30 showed presence of both resistant genes Ty-2 and Ty-3 at genotypic level. These promising genotypes will be useful as parental material to develop lines/hybrids carrying multiple genes against both monopartite and bipartite viruses for strong and durable resistance against ToLCV disease.

Composition and nematicidal activity of the essential oil from Piper longum against root knot nematode

Piper longum L. (Piperaceae family), commonly known as long pepper, is used in traditional medicine and in recognized system of medicine in India for the treatment of inflammation, pain, epilepsy, arthritis, cancer, ulcer, and asthma in addition to pest control activity. Its fruits are rich in essential oil and possess different biological activities, but oil is not much explored against the root-knot nematodes. Thus, the essential oil from the fruits of P. longum was isolated by hydrodistillation method and analyzed by Gas chromatography-Flame ionisation detector and Mass spectrometry. Analysis showed that the oil is a complex mixture of volatile compounds. (Z)-β-Farnesene (25.08%), β-Caryophyllene (13.57%), α-Humulene (13.37%), 8-Heptadecene (9.28%), Heptadecane (7.07%), α-Patchoulene (5.44%), 3-Heptadecene (5.09%), γ-Elemene (4.37%), β-Humulene (3.69%) and Terpinen-4-ol (1.74%) were identified as main compounds in its oil. The essential oil was evaluated for its nematicidal activity against root-knot nematode at 62.5–1000 ppm concentrations in vitro conditions during 2020–21 at ICAR-Indian Agricultural Research Institute, New Delhi. Results showed promising nematicidal activity of the oil and have caused mortality of juvenile (J2), ranging from 2.33–88.0% after 24–96 hours of treatment compared to untreated control. The oil was further evaluated under the pot conditions in tomato (Solanum lycopercicum L.) (var. Pusa Ruby) at 3000 and 2000 ppm. Results showed a significant reduction in the number of galls/root of tomato with better plant growth in the essential oil based treatment as compared to the untreated control. These results suggest that the oil can be used for the development of nematicidal product for the protection of crops from the infestation of M. incognita.

Evaluation of wheat (Triticum aestivum) genotypes for higher yield and enhanced nitrogen use efficiency in Indo-Gangetic Plains

Extensive research has been conducted on various nitrogen (N) management approaches to fulfil the growing needs of cereals while enhancing the efficiency of agricultural resource utilization. Nevertheless, the intensive agricultural model continues to prioritize the achievement of high crop yields and improving nitrogen use efficiency (NUE) as opposing targets. The primary aim of this study was to investigate whether a corresponding increase in N application is necessary to achieve higher crop yields. The study evaluated the effects of 3 N treatments (N0, N75, and N150) on 10 wheat (Triticum aestivum L.) genotypes during 2020–21 and 2021–22 at research farm of ICAR-Indian Agricultural Research Institute, New Delhi. In both growing seasons, the highest grain yield (GY) of 5.3 t/ha, agronomic efficiency (AEN) of 28.7 kg grain/kg N, and partial factor productivity of applied N (PFPN) of 60.2 kg grain/kg N were obtained by the HD 3249 genotype, followed by HD 3117. The application of N75 and N150 increased grain yields by 72.3 and142.6%, respectively, over N0. Significant relationships were observed between GY, PFPN and AEN at all N levels, and a decreasing trend was observed in both PFPN and AEN as the N application rate increased. The study results suggest that the adoption of genotype-specific nitrogen (N) rates could provide a mutually beneficial solution to meet the growing demand for food while improving NUE. Overall, based on GY and AEN, the research findings indicate that the genotypes HD 3249 and HD 3117 are efficient candidates for N use, with the potential for higher yields and NUE in the Indo-Gangetic plains of India.

Productivity and profitability of baby corn (Zea mays)-based cropping systems under various nutrient-management practices

A field experiment was conducted during 2016–17 to 2017–18 at the ICAR-Indian Agricultural Research Institute, New Delhi, to study the productivity and profitability of baby corn (Zea mays L.)-based cropping system under various cropping systems with different nutrient-management levels. The experiment was laid out in a split-plot design with 3 baby corn-based cropping systems (CSs) in main plots, viz. CS1 , rainy season baby corn-winter season baby corn-summer season baby corn (RBc – WBc – SBc); CS2 , RBc – WBc + vegetable fenugreek (Trigonella foenum-graecum L.) – summer season vegetable cowpea [Vigna unguiculata (L.) Walp.] (RBc – WBc + VFg – SCp); and CS3 , RBc – WBc + VFg – summer season sweet corn (RBc – WBc + VFg – SSc), and 5 nutrient-management levels, viz. N1 , 100% recommended dose of nitrogen (RDN) through urea fertilizer (100% RDN – F); N2, 75% RDN – F + 25% RDN through FYM (75% RDN –F + 25% RDN – FYM); N3 , 75% RDN – F + 25% RDN through vermicompost (75% RDN – F + 25% RDN – VC); N4 , 75% N % RDN – F + 25% N through leaf compost (75% RDN – F + 25% RDN – LC); and N5 , microbial consortium of Rhizobium/Azotobacter + phosphorus-solubilizing bacteria + potassium-solubilizing bacteria (R/Azo + PSB + KSB), in subplots. The yield of different component crops converted and presented in terms baby corn-equivalent yield (BCEY) for better understanding. Among the cropping systems, the BCEY differed from 1.99 to 2.18 Mg/ha during the rainy season. Baby corn CSs intensified with vegetable fenugreek during the winter season, resulted in significantly higher BCEY (2.42–2.52 Mg/ha) with CS2 and CS3 than the sole baby corn (CS1 ). Similarly, during the summer season, significantly higher BCEY (3.03–3.07 Mg/ ha) was recorded with CS3 . The cropping system CS2 recorded significantly lowest BCEY during both the years. The net returns in all CSs during rainy season was not differed significantly. During the winter season, significantly higher net returns (130–142 × 103 `/ha) were recorded in both the intensified cropping systems (CS2 and CS3 ) than CS1 (95–98 × 103 `/ha). During the summer season, significantly higher net returns (~186 × 103 `/ha) were recorded in CS3 than both CSs. Among the nutrient-management levels, significantly higher BCEY and net returns were recorded with 75% RDN – F + 25% RDN – FYM, followed by 75% RDN – F + 25% RDN – VC during both the years.

Effect of enriched composts and establishment methods on crop growth and nutrient concentration of rice (Oryza sativa) in trans-Gangetic plains of India

A field experiment was conducted during the rainy (kharif) seasons of 2018 and 2019 at the ICAR-Indian Agricultural Research Institute, New Delhi, to study the effect of crop-establishment methods and enriched organic nutrient sources on growth and productivity of ‘Pusa Basmati 1509’ rice (Oryza sativa L.). The experiment was laid out in splitplot design with 3 replications. The treatments comprised 2 main plot treatments, viz. aerobic rice (AR) and conventional transplanted (CT) rice, and 5 subplot treatments, viz. control (no fertilizer), 100% recommended dose of fertilizer (RDF)–100% mineral fertilization), 50% P through P enriched compost + 50% P through diammonium phosphate (DAP), 50% N through N-enriched compost + 50% N through urea and DAP and 100% organic (through N-enriched compost and P-enriched compost). The transplanted rice gave significantly higher grain yield (4.3 and 4.5 t/ha), straw yield (7.2 and 7.5 t/ha), plant height (97.8 and 99.1 cm), number of tillers (369.4 and 375.1), macro (1.4 and 1.3%-N, 0.14 and 0.15% -P, 0.27 and 0.28% K) and micro-nutrient concentration (70.5 and 76.8 ppm-Fe 22.2 and 22.9 ppm-Mn 24.1 and 24.7 ppm-Zn 10.1 and 10.5 ppm-Cu) in grain compared to aerobic rice. Enriched N compost having 50% N through N-enriched compost + 50% N through urea and DAP resulted in significantly higher grain yield (4.85 and 5.13 t/ha) than the other treatments except enriched P compost including 50% P through P-enriched compost + 50% P through DAP and these 2 treatments were at par in both the years. The 100% RDF resulted in more grain yield than 100% organic treatment, though differences were nonsignificant in both the years. Treatment of 50% N through N-enriched compost + 50% N through urea and DAP also resulted in taller plants, more tillers/m2 , higher macro and micro-nutrient concentration in grain than the other treatments. Hence, conventional transplanting of rice along with integrated application of enriched compost and inorganic fertilizer may be recommended to farmers for getting higher growth, productivity and better nutritional security.

Impact assessment of heavy metals spiked waste water irrigation on metals accumulation and translocation in marigold (Tagetes patula L.)

A pot experiment was conducted to find out the impact assessment of heavy metals spiked wastewater irrigation on growth, keeping quality and productivity of marigold (Tagetes patula L., cv.Pusa Arpita) at Water Technology Centre of ICARIndian Agricultural Research Institute, New Delhi during Rabi season of 2020-21. Sevan treatments were takenas T-1: Sole Groundwater Irrigation without spiking of heavy metal, T-2: Sole Wastewater Irrigation without spiking of heavy metal, T-3: Wastewater Irrigation spiked with Cd (0.005ppm), Cr (0.05ppm), Ni (0.1ppm) and Pb (2.5ppm), T-4: Wastewater Irrigation spiked with Cd (0.01ppm), Cr (0.1ppm), Ni (0.2ppm) and Pb(5.0ppm), T-5: Wastewater Irrigation spiked with Cd (0.1ppm), Cr (0.1ppm), Ni (2ppm) and Pb (10ppm) , T-6: Wastewater Irrigation spiked with Cd (0.25ppm), Cr (2.5ppm),Ni (5ppm) and Pb (30ppm), T-7: Wastewater Irrigation spiked with Cd (0.5ppm), Cr (5.0ppm), Ni (10ppm) and Pb (50ppm). Results indicated that Ni, Cr, Cd and Pb concentrations in the root part ranged from 2.05 to 54.48, 13.67 to 86.35, 0.89 to 5.21 and 3.84 to 22 mg/kg, respectively and in shoot parts ranged from 9.3 to 63.05, 29.99 to 97.4,1.8 to 6.42 and 12.38 to 29.93mg/kg, respectively, in marigold under different treatments of heavy metals spiked wastewater irrigation. Heavy metal translocation factors (TF) ranged from 0.22 to 0.87, 0.47 to 0.88, 0.38 to 0.82 and 0.32 to 0.75 for Ni, Cr, Cd and Pb, respectively and bioaccumulation factors (BF) for heavy metals (Ni, Cr, Cd and Pb) were varied from 63.8 to 114.47, 39.76 to 72.18, 34.21 to 64.57 and 6.3 to 12.61, respectively, in marigold under different treatments of heavy metals spiked wastewater irrigation. However, long-term application of heavy metals rich wastewater in marigold needs to be monitored at different soil and climatic conditions.

Impact assessment of heavy metals spiked wastewater irrigation on soil health in marigold (Tagetes patula L.)

A pot experiment was conducted to find out the impact assessment of heavymetals spiked wastewater irrigation on soil healthin marigold (Tagetes patula L., cv. Pusa Arpita) under irrigation with metals spiked wastewater at Water Technology Centre of ICAR-Indian Agricultural Research Institute, New Delhi during Rabi season of 2020-21. Sevan treatments were takenas T-1: Sole Groundwater Irrigation without spiking of heavy metal, T-2: Sole Wastewater Irrigation without spiking of heavy metal, T-3: Wastewater Irrigation spiked with Cd (0.005ppm), Cr (0.05ppm), Ni (0.1ppm) and Pb (2.5ppm), T-4:Wastewater Irrigation spiked with Cd (0.01ppm), Cr (0.1ppm), Ni (0.2ppm) and Pb (5.0ppm), T-5: Wastewater Irrigation spiked with Cd (0.1ppm), Cr (0.1ppm), Ni (2ppm) and Pb (10ppm) , T-6: Wastewater Irrigation spiked with Cd (0.25ppm), Cr (2.5ppm),Ni (5ppm) and Pb (30ppm), T-7: Wastewater Irrigation spiked with Cd (0.5ppm), Cr (5.0ppm), Ni (10ppm) and Pb (50ppm). Results indicated that soil health in-terms of pH, organic carbon, phosphorous, potassium and micronutrients (Cu, Fe, Mn, Zn) was significantly not changed where as significantly higher salinity (EC: 0.45 dS/m), nitrogen content (164.17 kg/ha) aswell as significantly higher concentration of Ni (0.76 mg/kg), Cr (1.66 mg/kg), Cd (0.18 mg/kg) and Pb (2.78 mg/kg) in irrigated soils were observed in the treatment T-7 where higher concentration of metals were spiked in wastewater. The present study may be concluded as the application of metals spiked wastewater irrigation may deteoriate the soil health by build-up of heavy metals under cultivation of marigold.

Impact of wastewater irrigation on physical health of soil and yield of marigold (Tagetes patula L. cv. Pusa deep)

A field experiment was conducted to find out the impact of wastewater irrigation on physical and microbiological soil health in marigold (Tagetes patula L. cv. Pusa deep) based on FDR sensor at Water Technology Centre farm of ICAR-Indian Agricultural Research Institute, New Delhi during period of 2020-2021. Eight treatments T-1: Groundwater irrigation scheduled at 25% MAD (v =27%); T-2: Groundwater irrigation scheduled at 50% MAD (v =22.5%) T-3: Groundwater irrigation scheduled at 75% MAD (v= 18%); T4: Groundwater irrigation scheduled as per farmers practice/recommended POP; T-5: Wastewater irrigation scheduled at 25% MAD (v= 27%); T-6: Wastewater irrigation scheduled at 50% MAD (v= 22.5%); T-7: Wastewater irrigation scheduled at 50% MAD (v= 18%); T-8: Wastewater irrigation scheduled as per farmers practice/recommended POP were laid out in a Randomized Block Design (RBD) with three replications. Results indicated that soil physical properties such as bulk density, saturated hydraulic conductivity and porosity at both the sol depths of 0-15 and 15-30 cm in marigold were significantly not changed due to application of wastewater irrigations scheduled at various range of MAD and with the use of FDR sensor. Significantly higher population density of faecal coliform bacteria was observed in treatment plot T-7 where wastewater irrigations were applied at MAD 50% as compared to groundwater irrigations. Moreover, the yield of marigold came to be high in wastewater irrigated plots compared to groundwater. Thus, short-term application of wastewater has less impact and the different ranges of MAD can be used for further studies.

Impact of wastewater irrigation on chemical properties of soil and flower quality of marigold (Tagetes patula L. cv. Pusa deep)

A field experiment was conducted to find out the impact of wastewater irrigation on physical and microbiological soil health in marigold (Tagetes patula L. cv.Pusa deep) based on FDR sensor at Water Technology Centre farm of ICAR-Indian Agricultural Research Institute, New Delhi during period of 2020-2021. Eight treatments T-1: Groundwater irrigation scheduled at 25% MAD (v=27%); T-2: Groundwater irrigation scheduled at 50% MAD (v =22.5%) T-3: Groundwater irrigation scheduled at 75% MAD (v= 18%);T4: Groundwater irrigation scheduled as per farmers practice/recommended POP; T-5: Wastewater irrigation scheduled at 25% MAD (v= 27%); T-6: Wastewater irrigation scheduled at 50% MAD (v= 22.5%); T-7: Wastewater irrigation scheduled at 50% MAD (v= 18%); T-8: Wastewater irrigation scheduled as per farmers practice/recommended POP were laid out in a Randomized Block Design (RBD) with three replications. Results indicated that soil chemical properties such as pH, organic carbon, EC, NPK and heavy metalat depth of 0-15 cm in marigold. As soil pH (7.80), EC (0.24 to 0.31 dS/m), OC (0.38), NPK and the concentration of heavy metals (Ni, Cd, Cr, Pb) were significantly higher in the treatment T6 where wastewater irrigations were scheduled at 50% MADas compared to groundwater irrigations. Moreover, the quality and grade of marigold came to be high in wastewater irrigated plots compared to groundwater. Thus, short-term application of wastewater has less impact over soil and gives better results in crop growth and quality but, the long-term application of wastewater may affect the chemical properties of the soil which can be analysed with different ranges of MAD (maximum allowable deficit) need to be studied.

Integrated nutrient management prescription for late-sown wheat (Triticum aestivum)

Integrated nutrient management prescription was developed for late-sown variety of wheat (Triticum aestivum L.) (HD 3059) through soil test based crop response study. A field experiment was conducted at the research farm of ICAR-Indian Agricultural Research Institute, New Delhi during winter (rabi) season of 2020–21 and 2021–22 to develop the integrated nutrient management prescription for late-sown wheat. Experiment was laid out in factorial randomized block design with 24 treatments having 3 levels of each N (60,120,180 kg/ha), P2O5 (30, 60, 90 kg/ha) and K2O (20, 40, 60 kg/ha). The basic parameters, viz. nutrient requirement (NR), percentage contribution of nutrients from soil (CS); fertilizer (CF) and farmyard manure (FYM) (CFYM) were quantified. Fertilizer prescription equations in integration with FYM were developed from the data obtained in the study. In order to produce 100 kg of late-sown wheat, the amount of major nutrients needed were 2.24 and 2.27, 0.45 and 0.47, 1.89 and 1.92 kg of nitrogen (N), phosphorus (P) and potassium (K) during 2020–21 and 2021–22, respectively. Phosphorus as soil nutrient contributed the maximum towards crop production; while the contribution of K from fertilizer (118.38 and 125.03) was highest for both seasons. Contribution of N from fertilizer (50.05, 51.38) was more than that of soil (33.81, 33.65). However, contribution of all the nutrients from FYM was lower. The equations developed were used to formulate ready reckoner for a range of soil test values to get a yield target of 55 q/ha for late-sown wheat. Nutrient management of late-sown wheat involving inorganic fertilizer in integration with FYM (10 t/ha) was prescribed through the ready reckoner. The study suggests that the excessive amount of fertilizer consumption as well as the subsequent adverse effect on the environment can be curtailed if FYM is used in combination with inorganic fertilizer.

The impact of different fertiliser management options and cultivars on nitrogen use efficiency and yield for rice cropping in the Indo-Gangetic Plain: Two seasons of methane, nitrous oxide and ammonia emissions

This study presents detailed crop and gas flux data from two years of rice production at the experimental farm of the ICAR-Indian Agricultural Research Institute, New Delhi, India. In comparing 4 nitrogen (N) fertiliser regimes across 4 rice cultivars (CRD 310, IR-64, MTU 1010, P-44), we have added to growing evidence of the environmental costs of rice production in the region. The study shows that rice cultivar can impact yields of both grain, and total biomass produced in given circumstances, with the CRD 310 cultivar showing consistently high nitrogen use efficiency (NUE) for total biomass compared with other tested varieties, but not necessarily with the highest grain yield, which was P-44 in this experiment. While NUE of the rice did vary depending on experimental treatments (ranging from 41% to 73%), 73%), this did not translate directly into the reduction of emissions of ammonia (NH3) and nitrous oxide (N2O). Emissions were relatively similar across the different rice cultivars regardless of NUE. Conversely, agronomic practices that reduced total N losses were associated with higher yield. In terms of fertiliser application, the outstanding impact was of the very high methane (CH4) emissions as a result of incorporating farmyard manure (FYM) into rice paddies, which dominated the overall effect on global warming potential. While the use of nitrification and urease inhibiting substances decreased N2O emissions overall, NH3 emissions were relatively unaffected (or slightly higher). Overall, the greatest reduction in greenhouse gas (GHG) emissions came from reducing irrigation water added to the fields, resulting in higher N2O, but significantly less CH4 emissions, reducing net GHG emission compared with continuous flooding. Overall, genetic differences generated more variation in yield and NUE than agronomic management (excluding controls), whereas agronomy generated larger differences than genetics concerning gaseous losses. This study suggests that a mixed approach needs to be applied when attempting to reduce pollution and global warming potential from rice production and potential pollution swapping and synergies need to be considered. Finding the right balance of rice cultivar, irrigation technique and fertiliser type could significantly reduce emissions, while getting it wrong can result in considerably poorer yields and higher pollution.

Metaheuristic approaches for prediction of water quality indices with relief algorithm-based feature selection

Monitoring and assessing groundwater quality are important for sustainable water resource management. Therefore, the present study aimed to analyze and predict the water quality indices using metaheuristics algorithms. Groundwater samples were acquired from 26 tube wells periodically, and laboratory analysis was performed in the soil and water laboratory, Water Technology Centre (WTC), ICAR-Indian Agricultural Research Institute (ICAR-IARI), New Delhi, India. Water quality parameters such as pH, electrical conductivity (EC), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), chloride (Cl−), carbonate (CO32−), bicarbonate (HCO3−) and sulphate (SO42−) were used for the computation of water quality indices. The relief algorithm was used for the selection of the best input combinations. Seven meta heuristics algorithms viz., Reduced Error Pruning Tree (REPTree), Random Forest (RF), Bagging, Additive Regression (AdR), M5Preuning Tree (M5P), Random Subspace (RSS), and Artificial Neural Networks (ANN) were trained and tested for Water Quality Index (WQI), and the best four candidate models, i.e., M5P, ANN, RF, and RSS were validated for the prediction of Kelly ratio (KR), sodium adsorption ratio (SAR), permeability index (PI), and percent sodium (%Na). The performance of models was assessed using statistical indicators, i.e., mean absolute error (MAE), root mean squared error (RMSE), Willmott index (WI), Nash-Sutcliffe efficiency (NSE), coefficient of correlation (R), and visual graphics (i.e., Taylor diagram and radar chart). On a quantitative comparative scale, the M5P model performed better for predicting WQI (WI = 0.997, NSE = 0.988, MAE = 7.173, RMSE = 10.769 and R = 0.999) and % Na (WI = 901, NSE = 0.692, MAE = 3.817, RMSE = 5.005 and R = 0.853). The ANN model had a significant edge over other models for predicting indices namely, KR (WI = 0.844, NSE = 0.625, MAE = 0.121, RMSE = 0.164 and R = 0.825), PI (WI = 0.987, NSE = 0.949, MAE = 2.508, RMSE = 3.269 and, R = 0.981), and SAR (WI = 0.981, NSE = 0.916, MAE = 0.314, RMSE = 0.385 and R = 0.976). The result indicated that the M5P model has the potential to predict the water quality indices even under limited input parameters scenarios in the sub-tropical climatic condition. Also, study findings revealed that the relief algorithm based input feature selection could be used for assessing water quality indices. The outcome of the present study would be of interest to policymakers or irrigation planners to achieve groundwater sustainability in terms of water quality suitability for distinct applications and remedial measures to enhance groundwater quality.

Enhancing maize yield in a conservation agriculture-based maize (Zea mays)- wheat (Triticum aestivum) system through efficient nitrogen management

This study evaluated the impact of contrasting tillage and nitrogen management options on the growth, yield attributes, and yield of maize (Zea mays L.) in a conservation agriculture (CA)-based maize-wheat (Triticum aestivum L.) system. The field experiment was conducted during the rainy (kharif) seasons of 2020 and 2021 at the research farm of ICAR-Indian Agricultural Research Institute (IARI), New Delhi. The experiment was conducted in a split plot design with three tillage practices [conventional tillage with residue (CT), zero tillage with residue (ZT) and permanent beds with residue (PB)] as main plot treatments and in sub-plots five nitrogen management options [Control (without N fertilization), recommended dose of N @150 kg N/ha, Green Seeker-GS based application of split applied N, N applied as basal through urea super granules-USG + GS based application and 100% basal application of slow release fertilizer (SRF) @150 kg N/ha] with three replications. Results showed that both tillage and nitrogen management options had a significant impact on maize growth, yield attributes, and yield in both seasons. However, time to anthesis and physiological maturity were not significantly affected. Yield attributes were highest in the permanent beds and zero tillage plots, with similar numbers of grains per cob (486.1 and 468.6). The highest leaf area index (LAI) at 60 DAP was observed in PB (5.79), followed by ZT(5.68) and the lowest was recorded in CT (5.25) plots. The highest grain yield (2-year mean basis) was recorded with permanent beds plots (5516 kg/ha), while the lowestwas observed with conventional tillage (4931 kg/ha). Therefore, the study highlights the importance of CA practices for improving maize growth and yield, and suggests that farmers can achieve better results through the adoption of CA-based permanent beds and use of USG as nitrogen management option.

First record of leafhopper genus Satsumanus Ishihara from India (Hemiptera: Cicadellidae: Deltocephalinae) with description of a new species.

The leafhopper genus Satsumanus Ishihara of tribe Opsiini is newly reported from India based on a new species, Satsumanus chajingensis Rajgopal & Stuti sp. nov. (Manipur: Imphal West), here described and illustrated. Materials are deposited in the National Pusa Collection, Division of Entomology, ICAR-Indian Agricultural Research Institute (IARI), New Delhi, India. Photographic illustrations, a species checklist, key to species of the genus and distribution map are provided.

Conservation tillage and microbially mediated integrated phosphorus management enhance productivity, profitability and energy use efficiency of maize

AbstractSustainability of maize production systems is threatened by poor economic returns and resource intensiveness. Therefore, an experiment was conducted at the ICAR-Indian Agricultural Research Institute, New Delhi during 2016–17 to 2017–18 to assess the effect of tillage and microbial inoculantsintegrated phosphorus (P) management on productivity, quality, economic outcome and energy dynamics of maize. Three tillage practices viz., CT–R (conventional tillage with no residue), ZT–R (zero tillage with no residue) and ZT + R (zero tillage with wheat crop residue at 2.5 Mg/ha) were assigned in main plots and five P management practices viz., P1 (control–NK as per recommendation, but no P), P2 (17.2 kg P/ha), P3 (17.2 kg P/ha + PSB), P4 (17.2 kg P/ha + compost inoculants) and P5 (34.4 kg P/ha) were allocated in subplots in three times replicated split-plot design. The maximum grain yield (5.96 Mg/ha), protein content (9.13%), protein yield (546 kg/ha) and gross energy returns (209 × 103 MJ/ha) were recorded under ZT + R while higher benefit: cost ratio (B: C ratio – the amount of economic gain per unit investment) (1.53) and energy efficiency (12.5) was noticed under ZT–R. Among the P management practices, the application of 34.4 kg P/ha recorded the highest grain yield (6.45 Mg/ha), protein content (9.34%), protein yield (603 kg/ha), B: C ratio (1.65) and energy efficiency (10.1). The results suggested that the application of P at the rate of 34.4 kg/ha under ZT + R is an economically robust approach for the quality maize production in semi-arid region.

Effect of polyhalite on growth and yield of wheat (Triticum aestivum) in India

A field experiment was conducted at ICAR-Indian Agricultural Research Institute, New Delhi, Research Farm during winter (rabi) season 2021–22 to evaluate the effect of multi-nutrient carrier polyhalite and its combinations with variable doses of MOP on growth parameters, yield, and productivity of wheat. The application of 100% K (polyhalite), i.e. T8 resulted in significantly higher growth and yield parameters of wheat, viz. plant height, dry matter accumulation, tillers numbers, crop growth rate, leaf area index, grain yield (5.87 tonnes/ha). A 7.5% increase in grain yield was observed with the application of T8 over T11. So, a balanced and prolonged supply of available nutrients with polyhalite to crop in a sustained manner can be maintained.

Productivity and profitability of drip fertigated wheat (Triticum aestivum) – mungbean (Vigna radiata) – maize (Zea mays) cropping system

An experiment was conducted at the research farm of ICAR-Indian Agricultural Research Institute, New Delhiduring 2019–20 and 2020–21 to study the productivity and economic viability of wheat (Triticum aestivum L.)–mungbean (Vigna radiata (L.) R. Wilczek)–maize (Zea mays L.) fertigated with 0, 60, 80, 100% recommended dosesof NPK and irrigated at 0.6 and 0.8 crop evapotranspiration (ETc) through subsurface (SSDI) and surface drip irrigation (SDI). The results were compared with the conventional practice of surface irrigation and soil application of 100% recommended doses of NPK. Grain yields of wheat, mungbean, maize and system wheat equivalent yield (SWEY) improved by 22.9, 7.2, 21.9 and 19.4%, respectively with increase in NPK fertigation doses from 60 to 100% and by 15.6, 9.2, 4.9 and 9.7% with the increase in irrigation frequency from 0.6 to 0.8 ETc. However, SDI and SSDI had equal system productivity (12.48 and 12.85 Mg/ha). The SWEY at 0.8ETc fertigated either with NPK80 or NPK100was statistically at par (14.2–15.9 Mg/ha) with the conventional practice (14.3–15.2 Mg/ha). The cash inflow, netincome and benefit cost ratio (BCR) of the cropping system also increased successively with increase in fertigationdoses and irrigation frequency. The net income and BCR followed the order maize>wheat>mungbean. The net income under SSDI at 0.8 ETc with NPK80 or NPK100 in wheat, mungbean, maize and system was 11–13, 88–105, 1-9 and 8–14% higher than the conventional practice. At 0.8 ETc and NPK100, BCR in SSDI (1.86) was higher than in SDI(1.71) and conventional system (1.67).