ABSTRACT
Increasing complexity in crop nutrient requirement in intensive crop production systems needs alternate multi-nutrient sources. Polyhalite (POLY-4) which contains 14% K2O along withcalcium (17% CaO), magnesium (6% MgO), and sulfur (19% S) can be a possible recourse in this regard. In maize-wheat systems, it was evaluated for productivity, profitability, nutrient usage, and nutrient use efficiency under Indo-Gangetic plain (IGP) zones for consecutive two years (2018-19 and 2019-20). The results revealed that 150% K through POLY-4 produced the maximum maize grain yield under the Trans Indo-Gangetic plains (TGP). The maize grain yield increased by 20.8% and 26.2% under 100% K (POLY-4) and 150% K (POLY-4) over No-K, respectively. But statistically, 100% K (POLY-4) stands similar with both 150% K (POLY-4) and 150% K through muriate of potash (MOP) and equivalent. The trends were noticed under upper Indo-Gangetic plain zones (UGP) also. Similarly, the maximum wheat grain yield (6.12 and 6.29 t/ha under TGP and UGP, respectively) was obtained under 150% K (POLY-4), and remained statistically at par with 100% K (POLY-4), but significantly higher than 150% K (MOP). Under both agro-ecologies i.e. TGP and UGP, the highest system productivity was obtained with recommended N, P, and 150% K application through POLY-4. The added return over NPK remained highest with 150% K (POLY-4) for both maize and wheat. However, higher partial factor productivity for N and S, agronomic, physiological, and translocation efficiencies were noticed under 150% K (POLY-4), and remained at par with 100% K (POLY-4). Increased system yield, added returns, partial factor productivity, agronomic, physiological, and translocation efficiencies under 100% K through POLY-4 (along with recommended N and P) proved its effectiveness as multi-nutrient source for the maize-wheat system under TGP and UGP.
ABSTRACT
By the year 2050, the world's population is predicted to have grown to around 9-10 billion people. The food demand in many countries continues to increase with population growth. Various abiotic stresses such as temperature, soil salinity and moisture all have an impact on plant growth and development at all levels of plant growth, including the overall plant, tissue cell, and even sub-cellular level. These abiotic stresses directly harm plants by causing protein denaturation and aggregation as well as increased fluidity of membrane lipids. In addition to direct effects, indirect damage also includes protein synthesis inhibition, protein breakdown, and membranous loss in chloroplasts and mitochondria. Abiotic stress during the reproductive stage results in flower drop, pollen sterility, pollen tube deformation, ovule abortion, and reduced yield. Plant nutrition is one of the most effective ways of reducing abiotic stress in agricultural crops. In this paper, we have discussed the effectiveness of different nutrients for alleviating abiotic stress. The roles of primary nutrients (nitrogen, phosphorous and potassium), secondary nutrients (calcium, magnesium and sulphur), micronutrients (zinc, boron, iron and copper), and beneficial nutrients (cobalt, selenium and silicon) in alleviating abiotic stress in crop plants are discussed.
