• 论文 •

人工控制土壤水分剖面调控根系分布的研究

1. 中国科学院国家计划委员会地理研究所, 北京　100101
• 出版日期:1997-09-15 发布日期:1997-09-15
• 基金资助:
国家重大自然科学基金

STUDIES ON THE CONTROL OF SOIL WATER PROFILE AND ROOT DISTRIBUTION

Feng Guanglong, Liu Changming

1. Institute of Geography, Chinese Academy of Sciences, Beijing 100101
• Online:1997-09-15 Published:1997-09-15

Abstract: There are feedback interrelationships between shoot and root, namely shoot growth and development could be controlled by root growth and distribution which can be also adjusted by soil moisture distribution in soil profile. In order to determine an optimum irrigation method for controlling water distribution with depths which could adjust effectively root growth and distribution in soil profile, the field experiment with four treatments of irrigation application depth and frequency (once irrigation, the same amount of water was irrigated by 1,2 and 3 times, respectively) were conducted from 1995-1996 at Luancheng Experimental Station of Agricultural Ecosystems, Chinese Academy of Sciences, which located in the North China Plain. Under different irrigation conditions, shoot growth, grain yield, root growth and distribution, soil water extraction patterns, consumptive water use, and water use efficiency (WUE) were investigated in detail. The more soil water content, the higher the rooting density, the density was reduced by decreased soil moisture content. Root length density was much more in the deeper layer due to soil water stress on the top of layer, meanwhile, more amount of soil water was depleted. Soil water extraction patterns were correlated to rooting distributions. Under frequent, light irrigation treatment (I3), soil moisture content and extraction efficiency were higher at 0 cm-30 cm layer in which 61% total root length density was observed, 74% total amount of water was consumed from the layer, the proportion of soil evaporation to evapotranspiration was 28% which was only 4% greater than the conventional irrigation (I1). Grain yield and WUE were improved separately by 17% and 11% in comparison with I1 treatment. Under I1 and rainfed treatment (CK), 37% and 30% total amount of root distributed in 50 cm-100 cm depth of soil from which 22% and 29% total amount of water were extracted, respectively. The crop achieved its maximum LAI and dry matter of stem and leaf at flowering stage, the rate of root elongation is the highest over growing season in the period (0.2 cm/cm 3穌-0.25 cm/cm 3穌). Average the maximum evapotranspiration rate (5.5 mm/d, 4.6 mm/d) and transpiration rate (4.6 mm/d, 3.3 mm/d) of all irrigation treatments occurred in flowering and filling stages. Otherwise, the average rate of soil evaporation is 1.3 mm/d during jointing stage which is the highest rate from jointing to maturing.

• S152.7