Multiannual soil mulching in agriculture: analysis of biogeochemical soil processes under plastic and straw mulches in a 3-year field study in strawberry cultivation

Abstract

Purpose The application of plastic mulching differs globally as well as climate, soils, crops, and agricultural practices, making it difficult to generalize the reported impacts on soil. Because literature is scarce about the influence of plastic mulching on soil under temperate, humid climate, the objective of this study was to understand how multiannual plastic mulching influences central soil parameters and processes under Central European cultivation conditions to evaluate its impact on soil quality in the long term. Materials and methods Central soil parameters and processes like leaching, aggregation, soil organic matter (SOM), and microbial biomass were investigated in a strawberry cultivation in Southwestern Germany. The field experiment compared a plastic-covered ridge–furrow system with subsurface drip irrigation (PC) to the same system with straw coverage (SC) in three soil layers (0–10, 10–30, and 30–60 cm) at seven dates within a 3-year period. Soil analyses comprised soil temperature and moisture, pH, bulk density, water-stable aggregates, soil organic carbon, dissolved organic carbon, and microbial biomass carbon and nitrogen. Results Rainfall infiltration impeded by PC reduces soil moisture but neither reduces leaching nor promotes (macro-)aggregate formation or stability; however, it maintains a loose and friable soil structure in surface soil (0–5 cm), compared to SC. PC promotes SOM accumulation and shifted SOM composition to a more hardly degradable SOM, especially below the topsoil (10–60 cm). Furthermore, PC revealed no indications of an increased microbial biomass or activity accompanied with an enhanced SOM decomposition due to the shifted microclimate. The seasonal, time- and depth-dependent effects, observed in some parameters, emphasize the importance to include them in future studies for a more holistic process understanding. Conclusion Our study showed no indications that multiannual plastic mulching influences soil quality within the 3 years of this study. Further research is advisable to support our findings on a larger scale and longer time periods and across various soil and crop types.

Effects of Straw Mulching and Reduced Tillage on Crop Production and Environment: A Review

“…Straw mulching and tillage either indirectly or directly improve soil fertility. Studies have shown that straw mulching not only increases soil temperature and moisture but also improves soil microbial biomass and nutrient cycling, thereby increasing the content of rhizosphere mineral nitrogen [96]. Straw mulching is itself a source of organic C and SOM which increase the availability of soil nutrients to plants and microbes [97].…”

Optimal Soil, Climate, and Management Factors for Maximizing Crop Yield and Soil Nutrients in a Rice–Oilseed Rotation System with Straw Return

“…The response of crop yield and soil nutrients to SR is also influenced by the initial soil properties [50,51]. The SOC is an essential indicator of comprehensive soil fertility [52]. Initial soil conditions such as high SOC were more suitable for increased oilseed rape yield under SR, while the opposite was true for increased rice yield.…”

Effects of Plastic versus Straw Mulching Systems on Soil Microbial Community Structure and Enzymes in Strawberry Cultivation

“…Thus, the nutrient status of the soil may additionally modulate the activity of acid phosphatase, in particular the P-sources and availability [82] determined in this study by the different fertilization patterns for SM (1 × 10 kg P) and PM (10 × 1.5 kg P). Also, lateral water flows together with the impervious matter of PM reducing rainfall infiltration may counteract nutrient leaching [83], with a better P-status in PM compared to SM. Straw amendments are known to support enzyme activity in soils [84].…”

“…These results should be considered, however, only as a temporary effect that is strongly modulated by climatic conditions such as temperature and rainfall events [97]. Temporal variations of temperature and soil water content have been observed in the course of long-term monitoring in PM and SM systems, derived from the nature of the mulching materials (i.e., optical properties) and the availability of water to infiltrate the soil after rain events [25,83].…”