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Imbalanced and indiscriminate use of chemical fertilizers has been adversely influencing the quality of soil, environment, biodiversity and nutrient status in soil. Conjoint application of bio-inoculants (BI) with organic or inorganic sources of nutrients tweaks nutrient synchrony in soil and improves plant nutrition. With this backdrop an experiment was conducted at Indian Agricultural Research Institute, New Delhi during 2016–2018. The objectives were to identify the suitable combinations of BI-mediated nutrient sources for higher productivity and profitability in pigeon pea–wheat cropping system (PWCS). The nine pigeon pea treatments; four sole applications viz., recommended dose of fertilizers (RDF), vermicompost (VC), farm yard manure (FYM), leaf compost (LC) and four conjoint applications viz., RDF + BI, VC + BI, FYM + BI and LC + BI and one control were replicated thrice under randomized block design (RBD). However, in succeeding wheat, each of the treatments applied to pigeon pea was further allocated to two levels (50% and 100%) in factorial RBD. Findings exhibit that FYM + BI could result into higher equivalent-system grain productivity (10.4 and 10.8 t ha−1 during 1st and 2nd year, respectively) of PWCS. However, profitability parameters of PWCS were higher with the RDF + BI. Uptake of nutrients (NPK) was significantly higher with FYM + BI in pigeon pea and RDF + BI in wheat. Nutrient harvest index (NHI) did not vary significantly in both the crops. Conclusively, bio-inoculation is more productive and beneficial in general, while, over the various combinations, recommendation of FYM + BI combination could be more productive and sustainable. [ABSTRACT FROM AUTHOR]

The experiments were conducted to evaluate the effects of silicon (Si) and phosphorus (P) application on crop productivity, grain quality, water-use efficiency (WUE), and soil enzyme activity in aerobic rice (AR) at Indian Agricultural Research Institute, New Delhi, India. Four levels each of Si (0, 40, 80, and 120 kg Si ha–1) and P (0, 30, 60, and 90 kg P2O5 ha–1) were tested in a factorial randomized block design (FRBD) replicated thrice. The growth, yield and quality of AR were enhanced with increasing Si and P application rates and a similar trend was observed for WUE and soil enzyme activity. The highest grain yield of AR was recorded with 120 kg Si and 90 kg P2O5 ha–1 followed by 80 kg Si and 60 kg P2O5 ha–1 and the lowest in control. The grain, straw yield and water productivity increased by 10–40%, 5–30%, and 10.2–39%, respectively in different treatments over control. Though, all studied parameters showed increment with increasing dose of Si and P; however 60 kg P2O5 and 80 kg Si ha–1 were statistically superior to their other respective doses. In conclusion, supplementation of Si and P fertilizers substantially increased the AR productivity in Trans-Gangetic plains of India (Figure 1). [ABSTRACT FROM AUTHOR]

Intense cultivation with narrow row spacing in wheat, a common practice in the Indo-Gangetic plains of South Asia, renders the crop more susceptible to lodging during physiological maturity. This susceptibility, compounded by the use of traditional crop cultivars, has led to a substantial decline in overall crop productivity. In response to these challenges, a two-year field study on the system of wheat intensification (SWI) was conducted. The study involved three different cultivation methods in horizontal plots and four wheat genotypes in vertical plots, organized in a strip plot design. Our results exhibited that adoption of SWI at 20 cm × 20 cm resulted in significantly higher intercellular CO2 concentration (5.9–6.3%), transpiration rate (13.2–15.8%), stomatal conductance (55–59%), net photosynthetic rate (126–160%), and photosynthetically active radiation (PAR) interception (1.6–25.2%) over the existing conventional method (plant geometry 22.5 cm × continuous plant to plant spacing) of wheat cultivation. The lodging resistance capacity of both the lower and upper 3rd nodes was significantly higher in the SWI compared to other cultivation methods. Among different genotypes, HD 2967 demonstrated the highest recorded value for lodging resistance capacity, followed by HD 2851, HD 3086, and HD 2894. In addition, adoption of the SWI at 20 cm × 20 cm enhanced crop grain yield by 36.9–41.6%, and biological yield by 27.5–29.8%. Significantly higher soil dehydrogenase activity (12.06 μg TPF g-1 soil hr-1), arylsulfatase activity (82.8 μg p-nitro phenol g-1 soil hr-1), alkaline phosphatase activity (3.11 n moles ethylene g-1 soil hr-1), total polysaccharides, soil microbial biomass carbon, and soil chlorophyll content were also noted under SWI over conventional method of the production. Further, increased root volumes, surface root density and higher NPK uptake were recorded under SWI at 20×20 cm in comparison to rest of the treatments. Among the tested wheat genotypes, HD-2967 and HD-3086 had demonstrated notable increases in grain and biological yields, as well as improvements in the photosynthetically active radiation (PAR) and chlorophyll content. Therefore, adoption of SWI at 20 cm ×20 cm (square planting) with cultivars HD 2967 might be the best strategy for enhancing crop productivity and resource-use efficiency under the similar wheat growing conditions of India and similar agro-ecotypes of the globe. [ABSTRACT FROM AUTHOR]

The practices of the System of Rice Intensification (SRI) methodology have been extended to wheat and various other crops with reported good results. To assess such reports with respect to wheat, an experiment was conducted at the Indian Agricultural Research Institute, New Delhi during 2011–2012 and 2012–2013. This experiment compared the performance of wheat under System of Wheat Intensification (SWI) and standard recommended practices (SRPs). In 2011–2012, the SWI yield of 7.93 t ha−1was 30% higher than for SRP in 2012–2013, climatically a less favorable year, hence SWI performed relatively better with a 46% yield advantage under climate stress. SWI produced 12.5% less in the stressful year, while the reduction for the SRPs ranged from 18% to 31%. Differences in yield attributes and root traits were also observed in favor of SWI. Available N, P, and K in the soil after harvesting was increased with SWI, whereas depletion in nutrients with the SRPs indicated the scope for SWI sustaining soil fertility. Higher yield compensated for higher SWI costs of cultivation. A net return of US$ 1383 ha−1was obtained with SWI, 35% more than the US$ 1020 ha−1from SRPs. Overall, SWI outperformed the SRPs in terms of yields, climate resilience, and economics. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa) is a staple food of more than half of the population of the world and provides food security and livelihoods for millions of population. Direct seeding of rice (DSR) refers to the process of direct sowing the seeds in the field rather than by transplanting seedlings from the nursery. Direct seeded rice is an age old practice and before the introduction of green revolution in India. Rainfed rice was often broadcasted into moist soil and crops were highly prone to weed competition resulted into low yield. Rice ecosystems and establishment methods determined the weed spectrum and degree of infestation in rice field (DSR). Weeds are considered as a major biological constraint in direct seeded rice. In direct seeded rice, weed management depend on weed flora, critical period of weed control, availability of water and method to be adopted. Integrated weed management (IWM) is essential to achieve the long term, sustainable and economic management of weeds in direct seeded rice. The literature regarding the direct seeded rice, critical period of crop weed competition, different types of weed flora and different methods for the effective and sustainable management of weeds in direct seeded rice are reviewed in this paper. [ABSTRACT FROM AUTHOR]

Intensive mono-cropping without a balanced supply of nutrients and declining water resources are degrading soil health, and as a consequence, agriculture production is becoming unsustainable and causing environmental degradation. The field experiment was conducted during Rabi season to assess the effect of an irrigation schedule, nutrient management, and wheat (Triticum aestivum L.) varieties on soil microbial biomass carbon (SMBC) and soil enzymes activities. Two nutrient levels, recommended rate of chemical fertilizer (RDF) and 50% RDF + 50% recommended dose of nitrogen (RDN) through farmyard manure (FYM) designated as Integrated Nutrient Sources (INS), and three irrigations levels, one irrigation at crown root initiation (CRI), two irrigations at CRI and flowering stages, and five irrigations at all main stages of the crop (CRI, tillering, jointing, flowering, and grain filling) were allocated to main-plots while four varieties of wheat, HD 2967, WR 544, HD 2987, and HD 2932, were allocated to sub-plots. The results revealed that SMBC and activities of dehydrogenase, alkaline phosphatase enzymes, and acid phosphatase were higher under restricted irrigation (irrigation at CRI stage) than other irrigation schedules. SMBC, dehydrogenase, acid phosphatase, and alkaline phosphatase activities were 73.0 µg g soil−1, 86.0 µg TPF g soil−1d−1, 39.6 µg PNP g soil−1 h1, and 81.8 µg PNP g−1 soil h−1, respectively, with the use of INS that was higher than RDF. Root weight and root volume followed a similar pattern. Applying single irrigation at CRI left behind the maximum available nitrogen (166.4 kg ha−1) in soil compared to other irrigation schedules and it was highest (149.31 kg ha−1) with the use of INS. Moreover, total organic carbon (TOC) was 0.44 and 0.43% higher with irrigation at CRI stages and the use of INS, respectively. The INS with single irrigation at the CRI stage is important to improve the root growth, SMBC dehydrogenase, alkaline phosphatase, and acid phosphatase enzyme activity in the wheat production system. [ABSTRACT FROM AUTHOR]

Field experiments were conducted during rabi / winter (November-March) seasons of 2011-12 and 2012-13 at research farm of Indian Agricultural Research Institute, New Delhi to evaluate the root growth and performance of wheat, chickpea and potato grown in different soybean-based cropping systems with 5 nutrient management practices. The results revealed that root growth in terms of root length, root volume and root dry weight of wheat and chickpea were observed significantly maximum where 50% RDN was substituted with FYM along with 50% RDF. Whereas, all the root parameters of potato were higher with the fertilization of 100% RDF. All the yield parameters and yields of wheat in soybean-wheat-fallow and soybean-wheat-mungbean cropping system did not differ significantly. All the yield parameters viz., effective tillers m-2, length of spike-1, grains spike and 1000-grain weight as well grain and stover yields of wheat were highest with the application of 100% RDF during both the years. Similarly, the maximum values of yield attributes and tuber and haulms yields of potato were recorded with the 100% RDF during both the years. However, no significant variation among all sources of nutrient was noticed during 2011-12 and among 100% RDF and substitution of 50% RDN through FYM during 2012-13 in both the crops. Whereas, significantly maximum yield contributing parameters and grain and stover yields of chickpea were found in the treatment receiving 50% RDF+50% RDN through FYM followed by 25% RDF+50% RDN through FYM+ biofertilizers during both the years. [ABSTRACT FROM AUTHOR]

A field experiment was conducted during 2010-2011 and 2011-2012 to investigate the effect of optimal (100% NPK) to super-optimal doses (200% NPK) of mineral fertilizers on soil enzymes such as dehydrogenase (DHA), acid phosphatase (Ac-PA), alkaline phosphatase (Alk-PA), fluorescien diacetate hydrolysis (FDA), urease and nitrate reductase (NRA) at three physiological stages (CRI, anthesis and maturity) of wheat crop on an Inceptisol. Dehydrogenase activity was reduced by 28-37% when fertilizer application was at super-optimal dose (200% NPK), whereas, urease and NRA responded positively in the range of 43-44% and 213-231% respectively. Alk-PA was 7.3-7.9% higher in treatments receiving 125% NPK as compared to control (100% NPK); whereas, Ac-PA declines in the plots receiving 175 and 200% of recommended dose of fertilizer (RDF) as compared to 150% NPK levels. Addition of 175% RDF increased the FDA to the tune of 46-53% as compared to 100% NPK. A significant (P≤0.05) positive interaction between fertilizer treatments and physiological stages of wheat growth was observed on soil enzyme activities (except urease and NRA) being highest at the anthesis stage of wheat. Correlation matrix analysis showed that DHA was correlated with the studied enzyme activities except Ac-PA and FDA; whereas, strong correlation was observed between urease and NRA (r=0.981, P=0.01). This study provides theoretical and practical base for avoiding super optimal application of fertilisers which hinders the enzyme activities and vis-a-vis sustainable nutrient enrichment under rhizosphere. [ABSTRACT FROM AUTHOR]