Efficiency of Reductive Soil Disinfestation Affected by Soil Water Content and Organic Amendment Rate

Xinqi Huang,Rui Zhu,Teng Wen,Jinbo Zhang,Zucong Cai,Xun Li

doi:10.3390/horticulturae7120559

Abstract

Reductive Soil Disinfestation (RSD) is a good method which can restore degraded greenhouse soil and effectively inactivate soil-borne pathogens. However, the approach needs to be optimized in order to facilitate its practical application in various regions. In the present work, we investigated the effect of soil water content (60% water holding capacity (WHC), 100% WHC and continuous flooding) and maize straw application rates (0, 5, 10, and 20 g kg−1 soil) on the improvement of soil properties and suppression of soil-borne pathogens (Fusarium oxysporum, Pythium and Phytophthora). The results showed that increasing the soil water content and maize straw application rate accelerated the removal of excess sulfate and nitrate in the soil and elevated the soil pH. Elevating the water content and maize straw application rate also produced much more organic acids, which could strongly inhibit soil-borne pathogens. Soil properties were improved significantly after RSD treatment with a maize straw amendment rate of more than 5 g kg−1, regardless of the water content. However, RSD treatments with 60% WHC could not effectively inactivate soil-borne pathogens and even stimulated their growth by increasing the maize application rate. RSD treatments of both 100% WHC and continuous flooding could inactivate soil-borne pathogens and increase the pathogens mortality indicated by cultural cells relatively effectively. The inhibited pathogens were significantly increased with the increasing maize application rate from 5 g kg−1 to 10 g kg−1, but were not further increased from 10 g kg−1 to 20 g kg−1. A further increased mortality of F. oxysporum, indicated by gene copies, was also observed when the soil water content and maize straw application rate were increased. Therefore, RSD treatment with 60% WHC could improve soil properties significantly, whereas irrigation with 100% WHC or continuous flooding was a necessity for effective soil-borne pathogens suppression. Holding 100% WHC and applicating maize straw at 10 g kg−1 soil were optimum conditions for RSD field operation to restore degraded greenhouse soil.

Highlights

Licensee MDPI, Basel, Switzerland.Greenhouse cultivation plays a very important role in vegetable production all over the world
The soil pH in all Reductive Soil Disinfestation (RSD) treatments was significantly increased at the end of treatments (Figure 1 and Table 3)
After the RSD treatments, soil pH was slightly increased in CK, and was further increased in RSD treatments

Summary

Introduction

Greenhouse cultivation plays a very important role in vegetable production all over the world. The health status of greenhouse soil directly influences the yield and the quality of the products from greenhouse cultivation [1]. Driven by the economic benefits, farmers usually apply a large amount of chemical fertilizer for intensive vegetable production in greenhouses in China [2,3]. Acidification and salinization widely occur in greenhouse soil, which greatly deteriorates the physical and chemical.

Objectives

Methods

Results

Discussion

Conclusion