Soft rock for improving crop yield in sandy soil in the Mu Us desert, China

Soft rock efficiently retains water because it is hard when dry but expands rapidly when wet, thus it can be used as a natural water retention agent. Therefore, soft rock can be blended with sandy soil to enhance the water-holding capacity of sandy land. Understanding how soft rock content in sandy soil affects corn growth (Zea mays L.) is essential for enhancing local agricultural production in the Mu Us Desert. The Root Zone Water Quality Model 2 was calibrated and validated based on 2-years of experimental data for composite soils prepared at three ratios of soft rock to sand (1:1, 1:2, and 1:5 v/v), and then used to estimate the water non-limiting potential yield (Yp) and the potential yield of a rainfed crop [Yp(r)], along with yield gap [YG(r)] of corn using the weather data from 1990 to 2013 in the Mu Us Desert. The mean simulated Yp(r) of corn in the compound soil at a ratio of 1:2 was significantly higher than that of the compound soil at 1:1 and 1:5 ratios, respectively. The mean simulated Yp(r)s of corn were 2.551, 3.527, and 2.924 Mg ha(-1) and the YG(r)s were 6.071, 5.096, and 5.698 Mg ha(-1) for 1:1, 1:2, and 1:5 ratios, respectively. The crop yield depends on the amount of soft rock added to the sandy soils.