ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

Takyric solonetz is spread mainly in arid area, Northwest China. Its poor soil structure and extremely low hydraulic conductivities (Ks< 0.1 mm/d) are the key factors restricting its amelioration. The ECe(electrical conductivity of saturated paste extract), SARe (sodium adsorption ratio of saturated paste extract), and pHs (pH of saturated paste) of the native soil studied at depth of 0~30cm were 12.30dS/m, 44.12 (mmol/L)0.5 and 9.33, respectively. After deep tillage, beds (1.0m width, 0.5m height) were formed. The drip lines were placed on beds covered with plastic. Lycium barbarum L. seedlings were then planted. A three-year field experiment was conducted to determine if reclamation could be achieved while cropping Lycium barbarum L. by using drip irrigation where soil beneath the drip emitters near the plants was replaced with sand in niches that were 0.2m ground diameter and 0.2m depth. The purpose of sandfilled niche was to increase the area over which infiltration of water occured thereby reducing the application rates to values that more closely matched the saturated hydraulic conductivity of the native soil, provide a reservoir for holding the applied water before it infiltrated and avoid the adversely mechanical impact and the stirring action of applied water on soil surface. Five treatments based on soil matric potential (SMP) thresholds used to trigger drip irrigation were designed to find the optimal drip irrigation schedule, i.e., -5kPa (S1), -10kPa (S2), -15kPa (S3), -20kPa (S4) and -25kPa (S5). The results showed that significant improvement was achieved in soil infiltration capability, which was demonstrated by the increasingly enlarged wetted area beneath the drip emitter. Consequently, a desalt region (ECe< 4dS/m) was formed, and high SMP level was favorable for the saltleaching in soil. The ratio of ECe/SARe was increased significantly after planting, which indicated the changes of soil salt composition characteristics and the amelioration of soil physical properties. After planting with drip irrigation, the contents of soil available nutrients were increased sharply. Nitrate nitrogen showed a high migration with water movement, and had potential to be lost by leaching, so nitrogen fertilizer should be applied in the later period during one irrigation event to reduce the leaching of nitrogen and raise fertilizer use efficiency. While available phosphorus was distributed mainly in depth of 0~20cm under drip emitter, due to its low migration with water. After three years experiment, S1 had the lowest survival rate (56.8%), and S3 got the highest (81.1%), S2, S3 and S4 gave higher fruit yields than other treatments significantly (p<0.05), which was around 900kg/hm2, and it was close to the level in local farmland. The findings indicated that a sandfilled niche beneath the drip emitter could be adopted for the reclamation of highly saline-sodic wasteland of takyric solonetz. Considering the factors, including soil watersalt properties, soil nutrients distribution and the growth of Lycium barbarum L., an SMP of -10kPa in the first two years and -20kPa from the third year could be used to trigger drip irrigation.