Effects of straw mulching practices on soil nematode communities under walnut plantation

Dagang Song,Fanjiang Zeng,Kaiwen Pan,Wenkai Chen,Yi Ran,Akash Tariq,Xiaoming Sun,Aiping Zhang

doi:10.1038/s41598-020-72530-5

Abstract

Agricultural management techniques such as mulching with crop straw can impact soil properties and may in turn change the structure and function of the soil food web. We investigated different straw mulching types and straw mulching coverage levels on soil nematodes community structure in walnut orchards. We set up a randomized experimental design with three straw mulch types, and three straw mulch distance treatments in a walnut plantation. The results indicated that the number of soil nematodes after straw mulching was lower than that found in the control (CK). However, the metabolic and structure footprints of the omnivore-predator nematodes showed higher values as compared to CK. The abundances of plant parasite and omnivore-predator nematodes were negatively correlated with ammonium nitrogen (NH4+–N) and dissolved organic nitrogen (DON), whereas soil moisture content (SM) had a negative correlation with the abundance of total nematodes. High structure index (SI), maturity index (MI) and low enrichment index (EI) values revealed a structured soil food web, medium soil enrichment, and fungal decomposition channel under the mix straw mulching treatments. Soil nematodes should be used as an indicator of soil functional changes resulting from straw mulching.

Highlights

Agricultural management techniques such as mulching with crop straw can impact soil properties and may in turn change the structure and function of the soil food web
It is clear that the Mix-n treatment had higher dissolved organic carbon (DOC) and NO3–N than the other treatments under all soil environmental conditions
We can explain the difference in soil nutrients by the soil biological composition of different straw mulching treatments

Summary

Introduction

Agricultural management techniques such as mulching with crop straw can impact soil properties and may in turn change the structure and function of the soil food web. We investigated different straw mulching types and straw mulching coverage levels on soil nematodes community structure in walnut orchards. Most studies of straw mulching have mainly focused on the physical, chemical and biological effects of soil and the physiological and ecological responses of mulched tree species to y ield[5,6,7]. Straw mulching is mainly concentrated on food crops, and there are few studies of straw mulching in orchards. With the growth of young walnut trees, the canopy width increases each year, so it is reasonable to designate the canopy radius at the coverage distance, considering the effect of canopy shading. Treatment Rice-n Rice-1.5n Rice-all n Rape-n Rape-1.5n Rape-all n Mix-n Mix-1.5n Mix-all n CK p value F

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Conclusion