半干旱黄土丘陵区春小麦生长的水分生态效应

Ecological Effects of Water on the Spring Wheat Growth in the Semi-arid Loess Hilly Area

在半干旱黄土丘陵区充足施肥条件下，灌水能使春小麦产量提高３０％—９０％。籽实产量与生殖生长期干物质积累呈正相关与营养生长期干物质积累呈负相关。综合考虑作物—气候—土壤条件，为有效利用水分，在春麦需水关键的６月中旬，进行补水灌溉，有利于春麦高产，灌水量以５０—１００ｍｍ为宜。

Irrigation can increase by 30 to 90 percent of the grain yeild of spring wheat with enough fertilizer applied in Guyuan county of the semi-arid loess hilly area. The amount of appropriate irrigation water is from 50mm to 100mm for effectively use water. It is shown by correlation coefficient that the grain yeild of the spring wheat increase with increasements of the dry mass of the vegetation growth stage, and decrease with increasement of the dry mass amount of the reproductive development stage. The key period of its reqirement water is the second 10-day of June. On the bas is of analysis crop-climate-soil satuation comprehansively. The suitable irrigation time should be on the later stage of the spring wheat developement under the condition of completement and health of its seedling.