Shifting Long-Term Tillage to Geotextile Mulching for Weed Control Improves Soil Quality and Yield of Orange Orchards

Abstract

Weed control in urban and peri-urban orange orchards is challenging due to operational and legislative restrictions. Tillage, besides from negatively affecting soil fertility and microorganisms, is demanding for humans. On the other hand, herbicides are advised against due to the possibility to reach waterbodies from the soil surface. Therefore, in urban and peri-urban areas, instead of tillage and herbicides, mulching with black plastic geotextile fabric is often used. This study aimed at assessing the impact of long-term soil mulching with black plastic geotextile fabric on soil fertility, microbial community and yield of an orange orchard in comparison to conventional tillage. To this aim, four soil management systems were set up: rotary tillage for the last 15 years, mulching with black plastic geotextiles for the last 15 years, rotary tillage for 7 years followed by mulching for the last 8 years, mulching for 7 years followed by rotary tillage for the last 8 years. Soil samples were analyzed to determine the chemical and biochemical parameters related to soil fertility. In addition, the abundances of the main microbial groups were investigated. Mulching increased soil total organic C at least by 65%. The greater soil organic C in mulched soil in turn contributed to increase the cation exchange capacity (+62% on average) and microbial biomass C (+120% on average). Additionally, the microbial quotient exhibited higher values in mulched soils compared to tilled ones, suggesting a greater soil organic matter accessibility by soil microorganisms. Moreover, mulching favored fungi over bacteria, and Gram-positive bacteria over Gram-negative bacteria, thus contributing to the establishment of a microbial community more efficient in utilizing C sources. The latter result was confirmed by the lower values of the metabolic quotient in mulched soil compared to tilled one. Overall, the black plastic geotextile fabric improved chemical and biochemical soil fertility that, in turn, lead to a higher orange yield in mulched soil.

Soil Quality and Crop Nutrition

“…The improvement in soil quality and fertility, in turn, leads to a higher orange yield in mulched soil. Moreover, Paliaga et al (2023) found that reversing mulching with tillage rapidly decreased soil quality and orange yield, thus confirming the deleterious effect of tillage especially in semiarid Mediterranean environments.…”

“…Additionally, soil mulching, especially in semiarid environments, may improve soil fertility and crop yield. The study of Paliaga et al [12] showed that mulching soil with black plastic geotextiles increased SOM, cation exchange capacity, microbial biomass, and microbial quotient, thus suggesting high SOM accessibility by soil microorganisms. Moreover, mulching favored fungi over bacteria, and Gram-positive bacteria over Gramnegative bacteria, thus contributing to the establishment of a microbial community more efficient in utilizing C sources.…”

From Waste to Resources: Sewage Sludges from the Citrus Processing Industry to Improve Soil Fertility and Performance of Lettuce (Lactuca sativa L.)

“…An aliquot of dried soil samples, moistened up to 50% of their water-holding capacity (WHC), was used for the determination of microbial biomass C and respiration (CO 2 emission). Microbial biomass C (MBC) was determined by the fumigation-extraction method [35,36]; it corresponded to the difference between organic C extracted by 0.5 M K 2 SO 4 from CHCl 3 -fumigated and not fumigated samples, multiplied by 2.64.…”

Effect of Different Mulching Practices on Bacterial Community Composition and Fruit Quality in a Citrus Orchard

“…The application of biomulching significantly alters the structure and function of the soil microbial community within the rhizosphere of wheat plants [62]. Moreover, the implementation of black plastic geotextile fabric has been shown to enhance both chemical and biochemical soil fertility, resulting in increased orange yields in mulched soil [71]. Mulching led to an increase in bacterial functional features, specifically those associated with amino acid transport and metabolism, as well as energy production and conversion [63].…”