水分胁迫条件下有机肥对小麦根苗生长的影响

水分胁迫条件下施用有机肥对小麦根苗生长的影响研究表明：随着水分胁迫程度的加剧，无论施肥与否，小麦根系均表现出根重下降、根长缩短、根活力降低、次生根数与根系吸收面积减小、根系SOD、POD活性明显降低、MDA含量和根冠比明显增高的趋势。但施有机肥促进小麦根系的生长，改善根系生理特性，增加根系吸收面积和活力，具以肥促根、以肥调水、延缓根系衰老的作用。有机肥和土壤水分对小麦产量的增加具有明显的正交互作用，特别是在小麦生长中心发生转换的关键时期，即拔节期，水肥的显著互作促进根系的生长，在一定程度上缓解干旱胁迫的影响，最终导致土壤水分利用率的提高和产量的增加。

Effects of Manure on Root and Shoot Growth of Winter Wheat under Water Stress

Crop root,an important organ for absorbing water and nutrients and synthesizing growth regulator,has a direct influence on the crop growth and yield.Roots play a remarkable role in dryland agriculture under serious soil water restriction.However,the research on crop root system is not so thorough as that on aerial parts of crop due to lack of advanced root treating techniques,suggesting that the study on roots is very important for the further improvement of the yield.The pot culture experiment was conducted on the Experimental Farm of Shanxi Agricultural University to determine if supplemental irrigation and/or application of soil amendments rich in organic matter could improve root growth of winter wheat(Triticum aestivum L.).Root length,root weight,root activity,adventitious root number,root total and active absorbing areas,root SOD and POD activities,root MDA content and root-to-shoot ratio of winter wheat were studied under three levels of soil moisture(13%,16%,20%) and three levels of fertilization(0,333 and 666 g cattle manure per pot were measured) during 20032004.The results indicated that the content of MDA and the ratio of root to canopy were increased,but the dry weight of root,total root length,adventitious root number,root activity,the SOD and POD activities of root,the total and active absorbing areas decreased significantly with drought treatment regardless of fertilizing or not;root growth,root physiological characteristics,seedling growth,the water use efficiency and the yield as well as drought resistance were improved(Table 3);the highest yield of wheat was found under F_3(666 g/kg) and W_3(soil water capacity 20%) treatment;.the activity of soil enzymes(Fig.2),especially in the rhizosphere could be increased by manure application,resulting in the improvement of soil nutrients,especially in the rhizosphere and enhancing the nutrients absorption and growth in wheat.