Effect of organic acid amendment on secondary saline soil amelioration in gully land consolidation area in northern Shaanxi, China

Abstract

He Kang (HK) is a widely used organic amendment for saline-alkali land improvement because of its effectiveness. This research evaluated HK’s effects on secondary saline soil amelioration in gully land consolidation area in the north part of Shaanxi, China. Experiments were conducted in field plots (4 m × 5 m) to test the effects of different HK contents (2.99 g/m2 (HK1), 3.74 g/m2 (HK2), 4.49 g/m2 (HK3), and 5.24 g/m2 (HK4)) on soil moisture water and salt content, nitrate nitrogen, available phosphorus, available potassium, and maize growth. The results showed that the salt contents in experimental plots with HK were lower compared with CK (no amendments), and soil water movement to deep soil was inhibited, and evapotranspiration was also decreased. HK improved the soil nutrient content and delayed the transport and leaching process of nitrogen, phosphorus, and potassium in the soil, which kept the nutrients in the root layer of spring maize plants in a higher concentration range. The uptake and utilization of soil nutrients by maize was promoted. Maize yields in plots with HK1, HK2, HK3, and HK4 were significantly increased by 21.51%, 34.34%, 22.10%, and 27.31%, respectively, compared with CK. The results indicated that HK is an effective method with 3.74 g/m2 (HK2) application rate of secondary saline soil amelioration in gully land treatment, which is beneficial to local crop growth.