A field experiment was carried out during therabiseason of 2004-05 to find out the effect ofRhizobiumand phosphate solubilizing bacterial (PSB) inoculants on symbiotic traits, nodule leghemoglobin, and yield of five elite genotypes of chickpea. Among the chickpea genotypes, IG-593 performed better in respect of symbiotic parameters including nodule number, nodule fresh weight, nodule dry weight, shoot dry weight, yield attributes and yield. Leghemoglobin content (2.55 mg g⁻¹of fresh nodule) was also higher under IG-593. Among microbial inoculants, theRhizobium+ PSB was found most effective in terms of nodule number (27.66 nodules plant⁻¹), nodule fresh weight (144.90 mg plant⁻¹), nodule dry weight (74.30 mg plant⁻¹), shoot dry weight (11.76 g plant⁻¹), and leghemoglobin content (2.29 mg g⁻¹of fresh nodule) and also showed its positive effect in enhancing all the yield attributing parameters, grain and straw yields.

Increasing ambient temperature is a major climatic factor that negatively affects plant growth and development, and causes significant losses in soybean crop yield worldwide. Thus, high temperatures (HT) result in less seed germination, which leads to pathogenic infection, and decreases the economic yield of soybean. In addition, the efficiency of photosynthesis and transpiration of plants are affected by high temperatures, which have negative impact on the physio-biochemical process in the plant system, finally deteriorate the yield and quality of the affected crop. However, plants have several mechanisms of specific cellular detection of HT stress that help in the transduction of signals, producing the activation of transcription factors and genes to counteract the harmful effects caused by the stressful condition. Among the contributors to help the plant in re-establishing cellular homeostasis are the applications of organic stimulants (antioxidants, osmoprotectants, and hormones), which enhance the productivity and quality of soybean against HT stress. In this chapter, we summarized the physiological and biochemical mechanisms of soybean plants at various growth stages under HT. Furthermore, it also depicts the mitigation strategies to overcome the adverse effects of HT on soybean using exogenous applications of bioregulators. These studies intend to increase the understanding of exogenous biochemical compounds that could reduce the adverse effects of HT on the growth, yield, and quality of soybean.

Mono-cropping of maize–wheat, mechanical disintegration of soils, and continuous chemical fertilization have deteriorated soil health in the Indo-Gangetic Plains. We studied the long-term impact of pulse-based cropping systems with integrated nutrient management on soil physical and chemical properties and yield sustainability. We evaluated four different cropping systems: (1) maize–wheat (M–W), (2) maize–wheat–mungbean (M–W–Mb), (3) maize–wheat–maize–chickpea (M–W–M–C), (4) pigeonpea–wheat (P–W) each with three degrees of soil fertilization techniques: (1) unfertilized control (CT), (2) inorganic fertilization (RDF), and (3) integrated nutrient management (INM). The field experiment was undertaken in a split-plot design with three replications each year with a fixed layout. P–W and M–W–Mb systems enhanced soil properties such as volume expansion by 9–25% and porosity by 7–9% (p < 0.05) more than M–W, respectively. P–W and M–W–Mb increased soil organic carbon by 25–42% and 12–50% over M–W (RDF). P–W system enhanced water holding capacity and gravimetric moisture content by 10 and 11% (p < 0.05) than M–W. Pulse-based systems (P–W and M–W–Mb) had higher available nitrogen (8–11%), phosphorus (42–73%), and potassium (8–12%) over M–W (p < 0.05). M–W–Mb increased 26% maize yield and 21% wheat yield over M–W (p < 0.05) at the thirteenth crop cycle. P–W system had a higher sustainable yield index (p < 0.05) of wheat over the M–W. Thus, pulse inclusion in the cropping system in combination with INM can enhance physical and chemical properties vis-à-vis sustainable yield index over the cereal-cereal system.

An insight into the dynamics of soil phosphorus (P) pools with long-term cropping/management practices would help in designing efficient and sustainable management module(s). The study aimed to investigate the long-term impact of diversified rice-based rotations and variable nutrient management practices on the dynamic composition of P pools and their influence on systems’ base-crop productivity in an alkaline soil of Indo-Gangetic plain (Fluvisol). Treatments consisted of four rotations [rice–wheat (R–W), rice–wheat–mungbean (R–W–Mb), rice–wheat–rice–chickpea (R–W–R–C), rice–chickpea (R–C)] each with three nutrient treatments [control (CT), integrated nutrient management (INM), sole-chemical fertilizers (CF)]. Notably, R–C exhibited higher levels of bioavailable-P (soluble-P, Ca₂-P, labile-Po), particularly in subsurface soil depth (0.2–0.4 m) compared to other rotations. Likewise, the inclusion of chickpea every alternate year (R–W–R–C) resulted in higher Ca₂-P (40%), labile-Pi (15%), labile-Po (11%), and moderately labile Po (8%) compared to R–W rotation demonstrating an increased significance of chickpea in maintaining a favorable soil P regime in alkaline soil. Both R–C and R–W–R–C reduced the surface-to-subsurface depth ratio (SSBR) of soluble-P and Ca₂-P while increasing the ratio for microbial biomass P. Even with a suboptimal fertilizer-P rate, INM significantly increased soluble-P (4–33%), labile-Po (13–17%), microbial biomass P (10–26%), moderately labile-Po (4–17%) compared to CF and exhibited higher SSBR values. Correlation analysis demonstrated the substantial influence of very-labile carbon, microbial and phosphatase activities on P availability. The treatment-induced changes in labile-P pools significantly influenced rice (base-crop) yields. In conclusion, chickpea-inclusive diversification and INM could be a sustainable approach to enhance P bioavailability and crop productivity in tropical rice soils.

Background: The negative effects of continuous use of chemical fertilizers on soil microbiology and agricultural sustainability are well established. The chemical fertilizers load in environment can be minimized by combined application of fertilizers and biofertilizers in crops like pulses which require less fertilizer-N and respond well to the use of biofertilizers. The objectives of the study were to see the effect of different biofertilizers in reduction of total fertilizer use and the response of field pea to combined application of chemical- and bio-fertilizers in terms of growth, yield and NUE. Methods: A field experiment was conducted during 2 consecutive rabi season of 2017-18 and 2018-19 at KVK, Chhatarpur, Jabalpur (Madhya Pradesh), India to evaluate the application of fertilizers and biofertilizers on growth parameter, nodulation, nutrient content and uptake, nutrient use efficiency, yield and economics of field pea. The experiment was laid out in randomized block design with five treatments in four replications. Treatments comprised of Control, Recommended dose (RD) of NPK (20: 60: 20 kg N, P2O5 and K2O/ha, respectively) (RDNPK), RDNPK + seed inoculation with Rhizobium @ 20 g/kg seed (RDNPK +R), RDNPK+R+phosphate solubilizing bacteria @ 20 g each/kg seed (RDNPK + R+PSB) and 75% of RDNPK + R+ PSB + potash solubilizing bacteria @ 5 kg/ha (75% RDNPK+ R+PSB+KSB). All other practices followed as per recommendation for the region and different observations and indices were recorded by following standard procedures. Conclusion: The application of 75% RDNPK+R+PSB+KSB was found best treatment among all others which resulted in highest grain yield (1682 kg/ha), protein content (23.1%), protein yield (388.5 kg/ha), net return (Rs. 46 623/ha) and B:C ratio (2.94). The nutrient use efficiency such as Partial Factor Productivity (PFP), Agronomic efficiency (AE), Physiological Efficiency (PE) and Economic Efficiency (EE) were also higher under combined application of fertilizers and biofertilizers. Thus, 75% RDNPK along with combined application of biofertilizers (R+PSB+KSB) may be applied for higher yield and return from field pea.