Exploring Optimal Cropping System to Improve the Water Use Efficiency and Soil Water Restoration after Lucerne-to-Crop Conversion in the Semiarid Environment

• Published in: Agronomy (Basel) Vol. 12; no. 8; p. 1905
• Main Authors: Wang, Linlin, Luo, Zhuzhu, Li, Lingling, Xie, Junhong, Fudjoe, Setor Kwami, Zechariah, Effah
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-08-2022
• Subjects: Agricultural production; Alfalfa; Analysis; Biomass; Bulk density; Carbon; China; Conversion; Corn; Crop production; Crop rotation; Cropping systems; Crops; Cultivation; Drought; Droughts; Economics; Fertilizers; Furrow systems; Harvest; Loess; lucerne–crop rotation; Medicago sativa; Moisture content; Moisture effects; Nitrogen; Organic carbon; Phosphorus; Polymer films; Potatoes; Productivity; Rain; Rain and rainfall; Recovery; Replenishment; Restoration; Rotation; Semi arid areas; Semi arid environments; Semiarid environments; Semiarid lands; Setaria italica; Soil density; Soil erosion; Soil fertility; Soil layers; Soil moisture; Soil water; soil water restoration; Solanum tuberosum; Triticum aestivum; Vegetables; Water content; Water supply; Water use; Water use efficiency; Wheat; Zea mays; China
• ISSN: 2073-4395; 2073-4395
• DOI: 10.3390/agronomy12081905

Due to depleting water supplies and the cultivation of high water-demanding crops such as lucerne, the effect of water deficits in crop production has become a major concern, especially in semiarid regions of China. A six-year field experiment (2012–2018) was conducted to evaluate soil water recovery and soil fertility after lucerne-to-crop conversions on the western Loess Plateau of China. Six rotation treatments (lucerne initially grew from 2003 to 2012 followed by the rotation of other crops or fallow until assessments in 2018) were: (1) lucerne (Medicago sativa L.)–lucerne (L-L); (2) lucerne–fallow (L-F); (3) lucerne–wheat (Triticum aestivum L.) (L-W); (4) lucerne–corn (Zea mays L.) (L-C); (6) lucerne–potato (Solanum tuberosum L.) (L-P); and (6) lucerne–millet (Setaria italica) (L-M). The same crops were grown each year after cultivation during 2013–2018. According to the findings, all rotation types gradually increased the soil water content, with the 0–110 cm soil layer experiencing the maximum soil water replenishment rate, followed by the 110–200 and 200–300 cm soil layers. After converting lucerne to crops, the amount of organic carbon, total nitrogen, and mineral nitrogen in the soil decreased, whereas total phosphorus and accessible phosphorus increased. Soil bulk density was reduced under rotation treatments. Soil water absolute restoration index was the highest under L-F, followed by L-C, L-W, L-P, and L-M. The rate of soil water recovery was 39.5, 33.0, 33.7, 33.5, 29, and 8.2 mm yr−1 under L-F, L-W, L-C, L-P, L-M, and L-L, respectively. The net economic return was greatest under L-C, followed by L-L, L-W, L-P, and L-M. From the analysis of the long-term experimental results, this study shows that the effect of soil water restoration is greatest when continuous alfalfa is converted into wheat, corn, and potato or fallow after 9 years. When the economic benefits and soil moisture recovery are considered comprehensively, corn sown in a ridge–furrow system with fully plastic film annual mulching is the most suitable field management practice after lucerne-to-crop conversion on the western Loess Plateau of China.