Soil aggregates stability and storage of soil organic carbon respond to cropping systems on Black Soils of Northeast China

Meng Zhou,Jie Wang,Xianfa Ma,Xiaobing Liu,Weiling Du,Ye Yuan,Xiannan Zeng,Jizhou Zhang,Guangwei Ding,Chunzhu Liu,Yingxue Zhu,Qingfeng Meng

doi:10.1038/s41598-019-57193-1

Abstract

Monoculture and improper management may reduce soil fertility and deteriorate soil structure in Black soils (Mollisols) of Northeast China. The experiment was carried out from 2015 to 2016 in Black Soils comprising five cropping systems: continuous corn (CC), soybean-corn rotation (SC), corn-soybean rotation (CS), fallow-corn (FC), and fallow-soybean (FS). Our results showed that CS and FS treatments significantly increased mean weight diameter (MWD) and fractal dimension (D) in mechanical stability aggregates (MSAs), and increased MWD and geometric mean diameter (GMD) in water-stable aggregates (WSAs) compared with CC treatment. These two treatments were also significantly increased water-stable aggregates stability rate (WSAR), but decreased percentage of aggregates destruction (PAD) than CC treatment. Meanwhile, CS and FS treatments exhibited a higher carbon accumulation than CC treatment in bulk soils. Soil organic carbon (SOC) concentration in WSA0.106-0.25,WSA2-5 mm and WSA0.5-1 mm had a dominant effect on aggregate stability. Simutaneously, SOC in WSA>5 mm affected SOC concentration in bulk soils. As a whole, the CS and FS treatments can increase the percentage of macro-aggregates, enhance aggregate stability, as well as increase SOC concentration in bulk soils and all soil aggregate sizes.

Highlights

Soil organic carbon (SOC) plays a key role in forming and stabilizing soil structure, enhancing soil physical properties, and nutrient recycling[1,2,3]
mechanical stability aggregates (MSAs) were mainly concentrated in MSA>5 mm, ranging from 35.4% in soybean-corn rotation (SC) treatment to 50.2% in FC treatment (Table 1)
We were surprised to find that SC treatment documented the highest proportion in the MSA0.5-1 mm (17.4%), MSA0.25-0.5 mm (6.5%), MSA0.106-0.25 mm (2.9%), and MSA

Summary

Introduction

Soil organic carbon (SOC) plays a key role in forming and stabilizing soil structure, enhancing soil physical properties, and nutrient recycling[1,2,3]. The soil organic matters of different cropping systems differed based on the quantity and quality of the crop residue coverage and the environment, affecting the organic carbon contents of the soil and the aggregate stability[18]. The larger the MWD and GMD values are, the higher the average particle size agglomeration of soil aggregates are, and the stronger the stability of soil structure is[20]. The Conservation Reserve Program (CRP) was proposed by the United States in 198634, and this measures can control soil erosion[35], improve water quality[36], protect biodiversity[37], create the habitat for wild animals and plants, and ameliorate agricultural non-point source pollution[38]. The experience is worth referencing with respect to land reclamation and land protection[39,40,41]

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Conclusion