Inadequate nutrient management is one of the major challenges for sustainable soybean production in semi-arid climatic conditions. Hence, a 3-year (2015–2017) field experiment was conducted to assess the effect of foliar application of macro- and micronutrients on the growth, productivity, and profitability of soybean. Eight foliar nutrient sprays at the pod initiation stage—water spray (WS), 2% urea solution, 2% di-ammonium phosphate solution (DAP_2%), 0.5% muriate of potash solution (MOP_0.5%), 2% solution of 19:19:19 nitrogen phosphorus and potassium (NPK_2%), and a 0.5% solution each of molybdenum (Mo_0.5%), boron (B_0.5%), chelated-zinc (Zn _0.5%) and no-foliar nutrition (NFN)—were compared with a basal-applied recommended dose of fertilizers (RDF: 30 kg N, 75 kg P, and 40 kg K ha⁻¹) in a randomized block design (RBD), replicated three times. Foliar-applied chelated Zn@0.5% (Zn_0.5%) at the pod initiation stage resulted in more pods per plants. In addition to Zn_0.5%, urea_2%, NPK_2%, and B_0.5% significantly improved the pods per plant over treatment by no-foliar nutrition (NFN). The RDF-supplied soybean subsequently sprayed with Zn_0.5% produced the highest seed yield, which was 18.5–37.8% higher than that of NFN treatment Yield improvement due to the application of B_0.5%, DAP_2%, and urea_2% varied between 19.2–23.7, 16.6–20.4 and 18.6–20%, respectively. Foliar nutrition showed the largest net returns from Zn_0.5%. The water-use efficiency (WUE) and production efficiency increased by 18.4–37.6 and 34.9–37.5%, respectively, due to Zn_0.5% over the efficiencies from NFN treatment. Monetary efficiency (ME) gains due to Zn_0.5% were 24% higher, while ME efficiency gains due to urea_2%, NPK_2%, and B_0.5% varied between 15–16%. Thus, this study suggested that the foliar application of 0.5% Zn and B, urea, NPK fertilizer, and DAP at 2%, along with RDF. is a profitable nutrient management option for quality soybean production in a semiarid region. However, nutrient partitioning, changes in soil chemical and biological indicators, and environmental aspects need critical examination in future studies.

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.

Phosphorus (P) and zinc (Zn) are essential plant nutrients, and their deficiency in soils and the antagonistic effect of P on Zn are important concerns world-over. Thus, a two-year (2012–13 to 2013–14) experimentation was carried out to assess grain yield, nutrient uptake and quality parameters of wheat by various levels of P and Zn. The results revealed that 50% recommended dose of P (RDP) through phospho-enriched compost (PEC) + 50% RDP through fertiliser and soil application of 12.5 kg ZnSO₄.7H₂O ha⁻¹ + one foliar spray of 0.5% ZnSO₄.7H₂O recorded significantly higher grain yield (4.81 and 4.61 t ha⁻¹, respectively), straw yield (7.20 and 6.92 t ha⁻¹, respectively) and protein content (11.5% and 11.3%, respectively). The concentrations of Zn in grain (35.6%) and straw (57.3%) were not affected due to organic P application but 100% P through P fertilizer reduced the Zn content in the grains. Both soil and foliar application of Zn were found to be more promising in increasing Zn and Fe concentration in grains (37.5 and 30.9 mg kg⁻¹, respectively) and straw (60.3 and 398 mg kg⁻¹, respectively). Overall, the treatment combination of 50% RDP through PEC + 50% RDP through fertiliser and soil applied 12.5 kg ZnSO₄.7H₂O ha⁻¹ + one spray of 0.5% Zn was beneficial in reducing antagonistic effect of P on Zn and increasing Zn and Fe concentration in wheat grain and, thus, could be used for improving the yield of Zn and Fe enriched wheat grains.

SUMMARY: Field experiments were conducted on a Typic Hapludoll (Mollisols) soil in the Indo-Gangetic Plains of India during the 2008 and 2009 rainy seasons to (1) find out the effect of irrigation schedules and plant spacing on physiological parameters, yield and water productivity of two rice cultivars under System of Rice Intensification (SRI), and (2) compare the performance of SRI with conventional transplanting (CT). Treatments under SRI included 12 combinations of three irrigation schedules,viz.irrigation at 1, 3 and 5 day(s) after disappearance of ponded water (DADPW), two spacing intervals (20 × 20 cm and 25 × 25 cm) and two cultivars (‘Pant Dhan 4’ and ‘Hybrid 6444’). The two control treatments were the CT of each cultivar. The experiment was set in a factorial randomized complete block design replicated thrice. The net photosynthetic rate (NPR) of the topmost fully expanded leaf at tillering and that of flag-leaf at flowering stage was affected significantly by irrigation schedules. Irrigating rice crop at 1 or 3 DADPW, being at par with each other, recorded significantly higher NPR than 5 DADPW. The increase in NPR at 1 and 3 DADPW was 17.1% and 8.4% at tillering and 13.6% and 6.1% at flowering stage, respectively, compared with that at 5 DADPW (tillering: 12.78 μmol CO₂m⁻²S⁻¹, flowering: 16.01 μmol CO₂m^‑2S⁻¹). At closer spacing (20 × 20 cm) the cultivars did not differ significantly for NPR; however, at wider spacing (25 × 25 cm), ‘Hybrid 6444’ showed significantly higher NPR than ‘Pant Dhan 4’. Between two methods, SRI recoded higher NPR. Dry matter accumulation (DMA) in leaves and grains declined with delay in irrigation from 1 to 5 DADPW. Wider spacing significantly enhanced DMA in stems and grains. ‘Hybrid 6444’ showed higher DMA in all plant parts than ‘Pant Dhan 4’. Grain yield was not affected significantly by irrigation schedules in 2008, while in 2009, irrigation at 1 and 3 DADPW resulted in 12.8% and 8.0% higher grain yield, respectively, than 5 DADPW (5.84 t ha⁻¹). Wider spacing was superior to closer spacing. SRI improved grain yield by 16.9% and water productivity by 18.5% over CT.