Analysis of vineyard soil after mulching with municipal solid waste (MSW)-compost

Abstract

The use of compost as amendment in agriculture is a well-established practice, strongly recommended for numerous benefits. Compost is a source of organic matter, necessary for both improving soil fertility and preventing erosion. Additionally, it provides nutrients for plants, allowing the reduction of mineral fertilization, and enhances soil microbial diversity both directly, by introducing a pool of microorganisms into the soil, and indirectly, by improving habitat suitability for microbial life. In the last years, compost has been also tested as mulching material for weed control as an alternative to plastic films, which generates pollution issues. Organic mulching allows reducing soil drying and regulates soil temperature fluctuations. Thanks to all these properties, use of high-quality compost is particularly recommended for marginal areas, such as Southern Italy, which are exposed to desertification risk and are increasingly threatened by climate changes.

In this study, a compost obtained from the organic fraction of municipal solid waste (MSW-compost), mixed with pruning waste and a minor fraction of agro-industrial sludge, was used for mulching in a wine vineyard in Salento (Apulia, Southern Italy). The vineyard soil was sandy loam and poor in organic matter (~ 10 g kg-1). Compost was applied in March along the row at three different doses (8, 15 and 22 kg plant-1) to create a mulching layer ~50 cm-wide and of increasing thickness depending on the amount of compost used. The compost treatments were compared with conventional mulching (black polyethylene film) and mulching with a biodegradable film. All the treatments, and the un-mulched control, were run in triplicate using a completely randomized design. Every three months, soil samples were collected and analysed for main physico-chemical parameters. Growth of weed plants along the row and crop morphological and yield parameters were also periodically measured.

Soil electrical conductivity slightly increased in all the treatments with compost, remaining always below the threshold of 2 dS m-1. The use of compost implemented the soil organic matter content and exerted an antigermination effect on weeds.