|
|
Distribution of soil water-stable aggrega- tes and organic carbon content affected by tillage systems: a meta analysis |
LU Xingli, LI Shanshan, LIU Jihu, DUAN Yaxin, YUE Heng, KANG Jianhong, WU Hongliang |
College of Agronomy, Ningxia University, Yinchuan, Ningxia 750021, China |
|
|
Abstract A better understanding of soil carbon(C)distribution within aggregate fractions is essential to evaluating the potential of no-till for sustaining productivity and protecting the environment. A meta analysis on 744 comparisons from 34 studies was conducted to determine the effects of three different tillage treatments(conventional mouldbould ploughing tillage(CT), reduced tillage(RT)and no tillage(NT))on water stable aggregate size distribution, soil C concentration in aggregate fractions. The meta analysis indicates that when compared with CT treatment, NT/RT significantly(P<0.05)increased macro-aggregate above 20 cm by 20.9%—82.2%(>2.00 mm)and 5.9%-19.1%(0.25-2.00 mm), whereas NT/RT significantly reduced micro-aggregate and silt clay fractions above 20 cm. NT/RT significantly(P<0.05)increased the SOC in macro-aggregate(>0.25 mm)and micro-aggregate(<0.25 mm)size classes above 20 cm soil depth as compared with CT. The results suggested soil sampling depth should be considered to evaluate the influence of tillage systems on the distribution of soil aggregate, and the content of aggregate-associated C content.
|
Received: 10 December 2019
|
|
|
|
|
|
|