Biochar and inorganic fertilizer when co‐applied have been reported to increase crop yield and enhance soil fertility. However, studies on this complementary effect on soil properties and noodle rice performance in China are still scanty. To investigate the effects of biochar application coupled with inorganic fertilizers on soil sustainability and yield and yield attributes of noodle rice, outdoor pot experiments were conducted in the early and late growing seasons in 2018. The treatment combinations were T1 (B0 t/ha + N270 kg/ha), T2 (B20 t/ha + N270 kg/ha), T3 (B40 t/ha + N270 kg/ha), T4 (B60 t/ha + N270 kg/ha), T5 (B0 t/ha + N360 kg/ha), T6 (B20 t/ha + N360 kg/ha), T7 (B40 t/ha + N360 kg/ha), and T8 (B60 t/ha + N360 kg/ha). The results compiled across the seasons showed an increase in Pn (net photosynthetic rate), grain yield, N uptake, gel consistency, amylose content (AC), and protein content in biochar‐treated pots as compared to T1. Average increases of 63.24, 63.66, 14.85, 58.0, 59.0, 22.39, and 2.9% were observed in soil porosity, moisture content, pH, organic carbon, total nitrogen, available phosphorus, and available potassium in T4 over T1 across the seasons, respectively. Root morphological characteristics such as total root length, surface area, volume, and average root diameter were significantly improved in T3, T4, T7, and T8. Starch‐related enzymes such as starch branching enzyme (SBE), starch debranching enzyme (DBE), and soluble starch synthase (SSS) were not affected significantly; however, granule‐bound starch synthase (GBSS), ADP‐glucose pyrophosphorylase (ADPG), and starch synthesis (SS) enzyme showed higher activity in 40 and 60 t B/ha across N rates. Conclusively, biochar application of 60 t/ha along with 270 kg N/ha is a promising option for improving soil quality and increasing photosynthesis, yield, and yield attributes of noodle rice.

The current farming system is heavily reliant on chemical fertilizers, which negatively affect soil health, the environment, and crop productivity. Improving crop production on a sustainable basis is a challenging issue in the present agricultural system. To address this issue, we assumed that the combined use of organic manure and inorganic nitrogen (N) fertilizers can improve rice grain yield and soil properties without the expense of the environment. This study explores the combined effects of cattle manure (CM), poultry manure (PM), and chemical fertilizer (CF) on soil properties, rice growth, physiology, and grain yield and quality. Six treatments in the following combinations were included: T1—no N fertilizer; T2—100% CF; T3—60% CM + 40% CF; T4—30% CM + 70% CF; T5—60% PM + 40% CF; and T6—30% PM + 70% CF. Results showed that across the seasons, treatment T6 increased the net photosynthesis rate, total biomass, grain yield, and amylose content by 23%, 90%, 95%, and 10%, respectively, compared with control. This increment in net photosynthetic rate and growth was the result of 24%, 14%, 19%, and 20% higher total root length, root surface area, root volume, and root diameter, respectively. Improvements in these attributes further enhanced the grain yield and nitrogen use efficiency of rice. No significant difference between T4 and T6 was observed. The correlation analysis also confirmed that root morphological traits were positively correlated with grain yield, N uptake, and biomass accumulation. Similarly, improvement in grain yield and NUE was also associated with improved soil properties, i.e., bulk density, soil porosity, soil organic carbon, and total N under combined organic and inorganic N fertilizers treatment. Conclusively, the integration of 30% N from PM or CM with 70% N from CF (urea) is a promising option not only for higher grain yield and quality of rice but also for improved soil health. This study provides a sustainable nutrient management strategy to improve crop yield with high nutrient use efficiency.

No abstract

Cotton (Gossypium hirustum L.) is grown globally as a major source of natural fiber. Nitrogen (N) management is cumbersome in cotton production systems; it has more impacts on yield, maturity, and lint quality of a cotton crop than other primary plant nutrient. Application and production of N fertilizers consume large amounts of energy, and excess application can cause environmental concerns, i.e., nitrate in ground water, and the production of nitrous oxide a highly potent greenhouse gas (GHG) to the atmosphere, which is a global concern. Therefore, improving nitrogen use efficiency (NUE) of cotton plant is critical in this context. Slow-release fertilizers (e.g., polymer-coated urea) have the potential to increase cotton yield and reduce environmental pollution due to more efficient use of nutrients. Limited literature is available on the mitigation of GHG emissions for cotton production. Therefore, this review focuses on the role of N fertilization, in cotton growth and GHG emission management strategies, and will assess, justify, and organize the researchable priorities. Nitrate and ammonium nitrogen are essential nutrients for successful crop production. Ammonia (NH) is a central intermediate in plant N metabolism. NH is assimilated in cotton by the mediation of glutamine synthetase, glutamine (z-) oxoglutarate amino-transferase enzyme systems in two steps: the first step requires adenosine triphosphate (ATP) to add NH to glutamate to form glutamine (Gln), and the second step transfers the NH from glutamine (Gln) to α-ketoglutarate to form two glutamates. Once NH has been incorporated into glutamate, it can be transferred to other carbon skeletons by various transaminases to form additional amino acids. The glutamate and glutamine formed can rapidly be used for the synthesis of low-molecular-weight organic N compounds (LMWONCs) such as amides, amino acids, ureides, amines, and peptides that are further synthesized into high-molecular-weight organic N compounds (HMWONCs) such as proteins and nucleic acids.

Poor seed germination is a crucial yield-limiting factor when winter wheat is sown under low temperature. The objective of this study was to evaluate the role of ascorbic acid (AsA) in the extenuation of the harmful effects of low temperature at early and reproductive stages of wheat during 2016–2017 (15 November to 15 December). A two-year experiment was conducted using a randomized complete block design with split plot arrangement and with three replicates. Sowing dates (15 November and 15 December) were allotted to the main plot while seed priming (control, hydro-priming, and AsA priming) were allotted to the sub-plot. Results demonstrated that AsA priming significantly boosted different yield characteristics including chlorophyll content, tillers per unit area, number of grains per spike, and 1000-grain weight, contributing higher productivity and biomass during 2016–2017. The results further revealed that AsA could induce the up-regulation of diverse antioxidants (super oxide dismutase (SOD), peroxidase (POD), and catalase (CAT)), thus offsetting the adverse effects of sub-supra optimum temperatures of late sowing wheat. It is therefore concluded in this work that AsA priming enhances stand establishment, yield and yield-related traits, antioxidant enzyme activities, and chlorophyll contents when wheat is sown under low temperature.