Strategies to alleviate the unusual effects of climate change on crop production: a thirsty and warm future, low crop quality. A review
Mohsen Janmohammadi, Naser Sabaghnia
Abstract
Climate change is one of the most common challenges in semiarid regions, which are affected by such constraints as drought, heat stress, and decreased soil fertility. The most important consequences of climate change – rising temperature, decreasing rainfall, and deteriorating quality of some crops – are studied in detail in this review. The main future climate scenarios in semiarid regions include decreased precipitation with highly irregular and unpredictable distribution patterns, with most rainfall concentrated over winter months, prolonged dry spells, early heat stress, exacerbation of edaphic constraints such as reduced soil moisture content, reduced soil organic matter, reduced soil biodiversity, reduced critical nutrient availability, and, ultimately, fewer crop yields. Due to the moisture and soil constraints caused by climate change, the cropping system, crop succession, and soil tillage techniques will need a major overhaul, and this requires modifying soil management and fertilisation, design of some new agro-climatic zoning, including neglected and underutilised crop species in rotations, optimised sowing time windows, expanded irrigation, design of multi-functional cropping systems, conservation agriculture, some changes in agricultural equipment, and the use of climate-smart agriculture practices. Rising carbon dioxide concentrations will decrease nitrogen metabolism by reducing photorespiration, and this reduces the protein content of the grain and worsens the quality of the staple crops. Selection of climate-smart varieties, application of agro-inputs at the right time, right place, and right amount (precision agriculture), and the use of leading technologies such as nano for designing the smart fertiliser should be considered to overcome the adverse effects of climate anomalies.