Effect of plastic film mulching and straw buried on soil water-salt dynamic in Hetao plain

In order to study the influence of different tillage adjustment measures on soil water and salinity distribution, field experiments were conducted under four tillage practices of plastic film mulching and straw buried (P+S), plastic film mulching(CKP), straw buried (CKS), and ploughing tillage(CKT) in Hetao Irrigation regions of Inner Mongolia. The results showed that the soil water content increased dramatically under the P+S, especially in the 20 to 40 cm depth. Compared to the treatments of CKP, CKS and CKT, the soil water content of 20 to 40 cm depth with P+S treatment increased by 20.69%, 5.62% and 38.03%, respectively, at the harvest stage. During the sunflower growth period, the P+S treatment cut down the soil salt content significantly. And its salinity accumulation was only 0.06 g per kilogram soil, less than those of the other treatments CKS, CKP and CKT by 35.11%, 133.78% and 276.89%, respectively. In addition, the salinity was fully eluted in the depth of 20 to 50 cm under the P+S treatment. Consequently, the P+S treatment established a favorable soil solution system to lower salt and increase moisture, which will be conducive to the root growth of sunflower in the seedling stage. Furthermore, the soil bulk density reduced while soil organic matter and moisture amount raised after the measures of P+S. For that, it suppressed the evaporation of grounder water which with higher degree of minimization prevented the salinity with water coming and assembling on the soil surface.