Application of Organic Fertilizers Optimizes Water Consumption Characteristics and Improves Seed Yield of Oilseed Flax in Semi-Arid Areas of the Loess Plateau

Abstract

Organic fertilizers are an important source of nutrients for improving farmland fertility. To explore high-yield, efficient and green production technology for oilseed flax in dryland agricultural areas, a field split plot experiment was conducted in the semi-arid area of the Loess Plateau in northwest China from April to August in 2020 and 2021. The study compared and analyzed the effects of different nutrient sources and their application rates on water consumption characteristics, grain yield and water use efficiency of oilseed flax. The main plots were fertilizer types (sheep manure, chicken manure and chemical fertilizer), while the subplots were fertilizer application rates (sheep manure: S1-12,500 kg·hm−2 and S2-25,000 kg·hm−2; chicken manure: C1-5800 kg·hm−2 and C2-11,600 kg·hm−2; chemical fertilizer: F1-N 112.5 kg·hm−2, P 75 kg·hm−2, K 67.5 kg·hm−2 and F2-N 225 kg·hm−2, P2O5 150 kg·hm−2, K2O 135 kg·hm−2). The results showed that compared with chemical fertilizers, organic fertilizers significantly increased the soil water storage capacity of the 0–160 cm soil layer during the whole growth period of oilseed flax and significantly reduced water consumption. During two growing seasons, the application of 25,000 kg·hm−2 sheep manure significantly reduced water consumption during the seedling-bud period and green fruit period-maturity period of oilseed flax by 16.13% and 23.19% compared with CK, respectively. Thousand-grain weight, yield and water use efficiency were significantly increased by 14.70%, 48.32% and 61.29%, respectively. These results indicate that the application of 25,000 kg·hm−2 sheep manure can significantly increase soil water storage capacity of the 0–160 cm soil layer, reduce water consumption during the whole growth period of oilseed flax and thus improve grain yield and water use efficiency of oilseed flax. It is a suitable fertilization technology for the high-yield, efficient and green production of oilseed flax in the semi-arid areas of northwest Loess Plateau.