不同灌水定额对北疆苜蓿叶面积指数和产量的影响

【目的】研究紫花苜蓿在浅埋式滴灌条件下,不同灌水定额对叶面积指数生长特性和产量的影响及二者之间相互关系。【方法】通过开展大田试验,共设置5个水分处理,依次为300 m3/hm2(T1)、375 m3/hm2(T2)、450m3/hm2(T3)、525 m3/hm2(T4)、600 m3/hm2(T5),采用植物冠层分析仪测量了不同灌水定额的紫花苜蓿叶面积指数和产量,分析相互关系,运用回归分析法拟合生长模型并进行验证。【结果】紫花苜蓿叶面积指数随着灌水定额的增大而增大,生长规律呈现先快后慢,倒"L"型趋势,2茬末期均出现衰败现象,第2茬受天气转冷因素表现更加明显。灌水定额525 m3/hm2以上叶面积指数没有明显提高,对应T4处理产量最高,叶面积指数、产量、灌水定额三者相互之间均存在显著相关性,建立三者之间相互单因素回归分析方程,拟合度较高。WUE随着灌水定额的增大呈现单侧下降趋势。【结论】运用浅埋式滴灌技术开展紫花苜蓿灌溉试验,适宜的灌水量可以改善紫花苜蓿生长状态,提高作物产量,达到节水增效的目的。

Effect to Leaf Area Index and Yield of Alfafa in North of Xinjiang by Different Irrigation Quota

【Objective】The purpose of this paper is to study the effect to leaf area index and yield of alfafa in north of Xinjiang by different irrigation quota and relation between leaf area index and yield in the condition of shallow drip irrigation. 【 Method 】 Regression analysis method was used to match plant growth model and then verified for 5 treatments in field test with irrigation quotas respectively of 300 m3/hm2(T1), 375 m3/hm2(T2), 450 m3/hm2(T3), 525 m3/hm2(T4), 600 m3/hm2(T5), measuring by plant canopy analyzer.【 Result】The leaf area index was rising with increasing irrigation quota. The growth of alfafa was faster at the beginning and then slower with the growth trend of inverted L-shape. Decline phenomenon was showed after two harvests, especially after the second harvest whose weather became colder. Leaf area index was not improved with irrigation quota over 525 m3/hm2. The yield was the highest by T4 treatment. Leaf area index, yield and irrigation quota had obvious correlation among them. Each single factor regression equation was established, and the fitting degree was higher. Water use efficiency had single-sided decline trend with increasing irrigation quota.【Conclusion】Using shallow drip irrigation, suitable irrigation quota can improve growth status of alfafa, achieving saving water and increasing yield.