Sustainable high yields can be achieved in drylands on the Loess Plateau by changing water use patterns through integrated agronomic management

Low yields of winter wheat are common throughout the Loess Plateau due to the region's erratic precipitation and the mismatch between the rainy season and the winter wheat growing season. In order to achieve sustainable high yields of winter wheat in this area, we set 6,000 kg hm(-2) as our yield goal and investigated the effects of four types of management systems, including a conventional farmers' management system and three integrated management systems, on winter wheat production over five consecutive years. The management practices varied in terms of seeding rates, nitrogen (N) application strategies, and application of manure or biochar. Our five-year study revealed that the average winter wheat yield under a manure integrated system (MIS) or a biochar integrated system (BIS) could achieve nearly 6,000 kg hm(-2) while also enhancing water use efficiency (WUE) to 1.63-1.69 kg m(-3). The high yields under MIS and BIS were mainly due to the large plant population that these systems permitted during the whole growing season, which was supported by favorable soil N levels (NO3--N content) and sufficient water supply. The high WUE under both systems was mainly due to decreased loss of precipitation (i.e., increased storage in the soil) during early growth stages (from sowing time to regreening stage) and increased use of subsoil water (100-300 cm) during late growth stages (from regreening to harvest time) by the large root system. In addition, the annual evapotranspiration under MIS and BIS was much lower than the annual precipitation in this area. Therefore, MIS and BIS are likely to be useful integrated management systems enabling sustainable high yields of winter wheat in the Loess Plateau through the regulation of water use patterns in both spatial and temporal terms.

Automated summary

The use of integrated management systems, such as the manure integrated system (MIS) or biochar integrated system (BIS), can significantly improve winter wheat yields and water use efficiency in the Loess Plateau by maintaining a stable plant population, ensuring favorable soil nitrogen levels, and providing sufficient water supply.