风沙土条件下滴灌灌水定额与深层渗漏量关系研究

保水、保肥性极差的风沙土广泛分布于和田地区,为探明滴灌条件下其灌水定额与深层渗漏量的关系以及确定适宜灌水定额,为和田地区设施农业的科学灌溉提供理论依据。以和田风沙土条件下日光温室萝卜地为研究对象,设置了5个灌水水平,开展定周期、变定额的灌溉试验,同时利用深层渗漏仪监测地面60 cm深度以下的深层渗漏量,分析了深层渗漏量与灌水定额之间的响应关系,结果表明:①试验条件下萝卜不同生育期发生深层渗漏的灌水定额临界值依次为苗期8.1 mm/次,叶部生长盛期与肉质根生长盛期10.4 mm/次;②T1~T5处理全生育期的深层渗漏量在26.0~254.7 mm之间变化;③风沙土条件下日光温室萝卜地深层渗漏量与灌水定额之间的关系可用以灌水定额为变量的一次与二次函数进行拟合,所得相关指数均在0.9以上,其中二次函数拟合效果较优。

Study on the Relationship Between Drip Irrigation Quota and Deep Seepage in Aeolian Sandy Soil

Aeolian sandy soil is widely distributed in Hetian area with poor water and fertilizer retention.In order to find out the relationship between irrigation quota and deep percolation in aeolian sandy soil and provide theoretical basis for scientific irrigation of facility agriculture in Hetian area,in this paper,the radish field in solar greenhouse in aeolian sandy soil in Hetian was taken as the research object,five irrigation levels were set to carry out irrigation experiment with fixed irrigation period and variable irrigation quota.At the same time,the deep percolation under the ground depth of 60 cm was monitored by the deep percolation meter,and the relationship between deep percolation and drip irrigation quota was analyzed.The results showed as follows:①The critical value of irrigation quota for deep leakage in different growth stages of radish was 8.1 mm/time at seedling stage,10.4 mm/time at leaf growth stage and fleshy root growth stage.②The deep leakage of T1-T5 treatments varied from 26.0 mm to 254.7 mm in the whole growth period;③The relationship between deep seepage amount and irrigation quota of radish field in solar greenhouse under the condition of wind-sand soil could be fitted with the primary and quadratic functions with irrigation quota as variables,the correlation indexes were all above 0.9,and the quadratic function had the better fitting effect.