Research On Water Use Efficiency For Alfalfa In Arid Area Of Central Ningxia

The entironment is week in arid area of central Ningxia. If pasture is planted,there will have good economic and ecological benefits. Alfalfa is a high-quality forage, and that have big value on feeding and nutritional. But, the alfalfa developed root system, and water consumption is larger, with the growth years increase, that will cause deep serious soil desiccation. In order to take into account the ecological and economic benefits. We use the water use efficiency as the core target, ten varieties of alfalfa materials were planted under three water conditions, i.e. severe drought stress, moderate drought stress, well watered in the arid area of central Ningxia, analyse the yield, water use efficiency, water consumption, carbon isotope discrimination, ash content, specific leaf dry weight, leaf relative water content, photosynthetic gas exchange parameters in leaf and whole plant. These will provide technical support and theoretical basis for the development of the livestock industry in Ningxia. The main results are as follows:(1) The performance of Yield and WUE on different Alfalfa under different water conditionThe yield and water use efficiency under different water conditions were significantly different. In water severe stress, Three Profits, Ningmu-No.l, Zhongmu-No.l,of water use efficiency and yield compared to other varieties of high; under supplementary irrigation conditions, Three Profits, Ningmu-No.1,Zhongmu-No.1, not only water use efficiency and high yield, hay and water consumption is relatively small. Different alfalfa varieties at different crop yield performance is different, the first crop yield was the highest, the third crop yield minimum, water use efficiency is the highest at middle stubble, the third stubble is minimum.(2) The Relationship of Yield and different index under different water conditionThe whole plant and leaf△has a significant positive correlation with yield on moderate stress; whole plant or leaf ash content and yield was negatively correlated in water stress; With the improvement of water conditions, leaf relative water content has a significant positive correlation with yield. Leaf ratio has a significant positive correlation with yield under certain water conditions; There was a apositive correlation between Plant height and yield..(3) The Relationship of△and different index under different water conditionThere was significant effect of water treatment on leaf and whole△, leaf ash content, specific leaf dry weight, photosynthetic gas exchange parameters. Specific leaf dry weight and whole plant△was negatively correlated under severe drought stress. Leaf relative water content was positively related with whole plant△under severe drought stress and moderate drought stress. Negative correlation between ash content and△in whole plant was found under severe drought stress and moderate drought stress. It was accordingly concluded that specific leaf dry weight, leaf relative water content and whole plant ash content might be considered as the substitution indexes of carbon isotope discrimination to predict transpiration efficiency of alfalfa under water limited condition in the arid area of Ningxia.(4) The overall performance of different alfalfa varietiesNingmu-No.1.Three Profits, Zhongmu-No.l, Ningmu-No.2, the whole plant or leaf△is relatively high. Ningmu-No.1,Three Profits, Zhongmu-No.1,of whole plant and leaf ash content is low. The high leaf relative water content of alfalfa is Ningmu-No.1,Three Profits, Zhongmu-No.1. Ningmu-No.2, Gannong-No.3and Guyuanzihua were water-consumption types, Ningmu-No.1, Zhongmu-No.1and Three Profits were water-saving types, These save-water cultivars should be planted as to make best use of the limited rainfall resources in the arid area of central Ning.