干旱荒漠绿洲紫花苜蓿的节水灌溉及水效益分析——以民勤县为例

Analysis on Water-saving Irrigation and Water Effectiveness of \%Medicago sativa\% in Arid Desert Oasis ——An Example of Minqin County

通过对民勤绿洲区8个紫花苜蓿品种的节水灌溉技术研究,分析得出紫花苜蓿在刈割前10d灌溉的平均耗水系数比刈割后灌溉的平均耗水系数降低18 6%,平均水效益提高23 3%;采用沟畦小块(面积0 03hm2)刈割前10d灌溉的紫花苜蓿平均耗水系数为0 228kg·g-1,平均水效益为4 39kg·m-3,平均水经济效益为8 78元·m-3;是沟畦小块(0 03hm2)灌溉小麦耗水系数的47 2%,水生产效益的212%,水经济效益的309%。不同紫花苜蓿品种间水效益的研究表明,加拿大RangerLander、Kane和新疆大叶苜蓿的水效益明显高于对照品种的水效益。同时,通过对干旱荒漠区水资源紧缺、水资源有效利用率低以及种植业结构不合理的现状分析,提出了改革种植业内部粮经饲以往的面积比例65∶32∶3为可行比例1∶1∶1,以大力发展优良品种紫花苜蓿草产业为突破口,走紫花苜蓿产业化道路最终实现高效节水持续农业的对策。

Research on water-saving irrigation for 8 varieties of \%Medicago sativ \%has been conducted in Minqin Oasis. The water consumption coefficient can be reduced by 18\^6% when \%Medicago sativa\% were irrigated on 10 days before cutting than after cutting, and the average water effectiveness can be increased by 23\^3%; when irrigated on 10 days before cutting and with small strip(0\^03 hm^(2)) irrigating method the average water consumption coefficient of\% Medicago sativa\% was 0\^228 kg\5g^(-1), the average water effectiveness was 4\^39 kg\5m^(-3) and the average water economic benefit was 8\^78 Yuan\5m^(-3), which respectively was only 47\^2% water consumption coefficient of wheat in same condition as \%Medicago sativa\%, but 212% water effectiveness and 309% water economic benefit of wheat. Irrigation research among different \%Medicago sativa\% varieties shows that the species of Ranger Lander and Kane from Canada and broad-leaf one from Xinjiang of China remarkably had higher water effectiveness (\%P\%<0.05) than the checking species. Suggested by situation analysis on water resources shortage, low water effectiveness and irrational cultivating structure, the area proportion of crop to cash crop and to fodder should be adjusted from 65∶32∶3 of the past to 1∶1∶1 in plan; for realizing high-effectively water-saving and sustainable agriculture a feasible strategy is to take prataculture of good specie \%Medicago sativa\% as the start and gradually go into its industrializing road.