[Effects of straw mulching on the soil aggregates in dryland wheat field under no-tillage].
A field experiment was conducted to study the effects of full period and growth period straw mulching with an amount of 3000, 6000, and 9000 kg x hm(-2) on the soil aggregates in a no-tillage dryland wheat field in Weibei Loess Pleateau of Shaanxi Province, taking no full period straw mulching as the control. In the 0-40 cm soil layer, the content of > 5 mm aggregates increased with depth, while that of <5 mm aggregates was in adverse. Under straw mulching, the total contents of > 0.25 mm mechanical stable aggregates (DR0.25) and of > 0.25 mm water stable aggregates (WR0.25) were significantly higher than the control, with an increase of 13.0%-26.4% and 18.6%-45.6%, respectively and the largest increment in the treatment 6000 kg x hm(-2) of straw mulching. Straw mulching increased the soil organic matter content, and the latter had a significant positive correlation with the WR0.25 content. All the straw mulching treatments decreased the soil unstable aggregate index (E(LT)) which was the lowest in treatment 6000 kg x hm(-2) of straw mulching. This study showed that straw mulching could increase the >0.25 mm aggregates and organic matter contents in 0-40 cm soil layer and improve the soil structural stability, and mulching with an amount of 6000 kg x hm(-2) had the best effect, being a reasonable straw mulching mode to be applied in the agricultural production in Weibei Loess Plateau.
Minister of Agriculture Key Laboratory of Crop Physi-ecology and Tillage Science in Northwestern Loess Plateau, Chinese Research Institute of Water-saving Agriculture in Dry Area, Northwest A & F University, Yangling 712100, Shaanxi, China. whx2009_6005@sina.com
Hai-Xia
HX
Wang
Hong-Xia
HX
Sun
Qing-Fang
QF
Han
Min
M
Wang
Rui
R
Zhang
Zhi-Kuan
ZK
Jia
Jun-Feng
JF
Nie
Ting
T
Liu
D000383:Agriculture / Q000379:methods*; D002681:China; D055864:Droughts; D017753:Ecosystem; D018547:Plant Stems / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D014908:Triticum / Q000737:chemistry / Q000254:growth & development*; D014867:Water / Q000032:analysis
D012987:Soil; D014867:Water