论文部分内容阅读
通过田间滴灌试验 ,研究了在不同滴头出水流量条件下干旱沙地土壤水分、盐分运移与分异过程 ,并调查作物的根系分布。结果表明 :微灌系统仅给作物根际分布区以内的小面积土壤供水 ,并未使整个土表面均匀湿润 ,对于大多数农田而言 ,其优点是有限的湿润表面积能够限制杂草生长 ,减少土壤表面无效蒸发。但干旱区潜在蒸发量大 ,滴灌条件下水分运移的过程将引起和支配耕作层盐分的移动和重新分配。当水盐混合溶液 (无机肥料溶液 ,N∶ P∶ K=12∶ 6∶ 6 )在 3种处理中 (0 .3L/ h,0 .8L/ h,2 .0 L/ h)由滴头流动至根系湿润区内 ,水分、养分被作物根系吸收 ,部分水分直接蒸发至大气后 ,过剩盐分将留存下来 ,并在土体表面和土体内湿润边界层逐渐积聚 ,形成高盐分聚集区。由作物根系分布特点看出 ,处理 、处理 有利于提高根系单位土体分布密度 ,处理 次之
Field drip irrigation experiments were conducted to study the process of soil water and salinity transport and differentiation under different drip flow rates and to investigate the root distribution of crops. The results showed that the micro-irrigation system only supplied water to a small area of soil within rhizosphere distribution of crops and did not make the entire soil surface wet uniformly. For most of the farmland, the advantage was that the limited wetted surface area could limit the growth of weeds and reduce Soil surface invalid evaporation. However, the potential evapotranspiration in the arid region is large and the process of water transport under drip irrigation will cause and control the movement and redistribution of salt in the tillage layer. When the water-salt mixed solution (inorganic fertilizer solution, N: P: K = 12: 6: 6) The water and nutrients are absorbed by crop root system. After some of the water is directly evaporated to the atmosphere, excess salt will be retained and gradually accumulate on the soil surface and in the wet boundary layer to form a high salt concentration area. It can be seen from the distribution characteristics of crop roots that the treatment and treatment are beneficial to increase the distribution density of soil in the root unit,