Contact/s:
Sara Carè
sara.care@crea.gov.it
Green Manure: Environmental Measure for Sustainable Fruit Production
Italy
Mediterranean Area
- Farm production efficiency
- Environmental sustainability
- Mitigation strategies
Thematic Areas
Production System/s
Summary for Practicioners on the Main Finding(s)/Innovative solution(s)
Among the agronomic practices used to increase fertility, improve soil structure, enhance biodiversity and reduce the environmental impact of agricultural systems, green manure plays a key role. It is referred to as green manure because it can replace animal waste in the organic fertilization of cultivated land. This practice is widely used in horticulture to counteract the deterioration of soil fertility.
Green manure involves sowing specific intercalary herbaceous plants in rotation with high-income crops. The goal is to bury these plants to improve the productive performance of the next horticultural crop, orchard, or vineyard. However, its primary function is to increase organic matter in the soil by incorporating the plant mass, with all the resulting benefits.
The maximum benefit of this practice is achieved by using legumes, grasses, or buckwheat, which effectively absorb nitrogen. Ideal seed mixtures should have biological cycles of similar duration to ensure uniform flowering. Additionally, mixtures with coarse shredding should be used, with residues left to dry in the field before burial, maximizing the organic matter contribution to the soil.
Following these simple guidelines, combined with careful planning, allows farms to add large quantities of high-quality organic material to the soil. This enriches the soil with key biological fertility factors, benefiting farms by providing a more productive substrate.
A carefully chosen green manure composition also helps prepare a more favorable growing environment for the next crop, ensuring better agricultural results.
Summary for Practicioners in Native Language
Fra le pratiche agronomiche usate per aumentare la fertilità, migliorare la struttura del suolo, migliorare la biodiversità e diminuire l’impatto ambientale dei sistemi agricoli c’è il sovescio che viene definito come letame verde, perché può, appunto, sostituire le deiezioni animali nella concimazione organica dei terreni coltivati. Questa pratica agronomica viene utilizzata nell’orticoltura per contrastare il deteriorarsi della fertilità. Il sovescio è una tecnica che consiste nella semina di specifiche erbacee intercalari in rotazione con colture ad alto reddito. Lo scopo è quello di interrare le intercalari e migliorare così le performance produttive della coltura orticola successiva in rotazione oppure di un frutteto o di un vigneto. La funzione fondamentale del sovescio è comunque l’aumento di sostanza organica nel suolo, conseguente all’interramento della massa vegetale, con tutti i benefici che ne derivano. La massima utilità di questa pratica si ottiene utilizzando leguminose, graminacee o grano saraceno che assorbono azoto; miscugli che abbiano cicli biologici di durata molto simile in modo tale da avere una fioritura omogenea, miscugli che abbiano una trinciatura grossolana i cui residui siano lasciati essiccare in campo prima dell’interramento in modo tale da apportare una levata quantità di sostanza organica nel terreno. L’osservazione di queste semplici “regole” unita ad una precisa programmazione permette alle aziende di apportare la terreno grandi quantità di sostanza organica di qualità elevata. Il terreno così si arricchisce di tutti quei fattori che ne vanno a comporre la fertilità biologica a tutto vantaggio delle aziende che possono disporre di un substrato su cui produrre con migliori risultati. La scelta oculata della composizione del sovescio consente poi di preparare, già in questa fase, un substrato più “accogliente” per la coltura che lo seguirà.
Additional Information
Among the agronomic practices used to increase fertility, improve soil structure, enhance biodiversity, and reduce the environmental impact of agricultural systems, green manure plays a key role. It is called green manure because it can replace animal waste in the organic fertilization of cultivated land. This practice is used not only on conventional and organic farms but is also widely adopted in fruit-producing farms to counteract soil fertility loss.
Green manure involves alternating normal crops with specific plant families that have particular characteristics. These plants are chopped and buried, enriching soil fertility. This technique allows for a significant increase in organic matter when manure is not available.
The benefits of green manure include:
• Better nitrogen management: Root nodules, especially those of legumes, fix atmospheric nitrogen (N₂), making it directly available to plants.
• Improved soil structure: Makes the soil softer and more workable while increasing water and nutrient retention.
• Erosion prevention: Enhances structural stability and protects against erosion and weathering, thanks to the surface layer of plant sand the root system in the subsoil.
• Natural pest control: Green manure crops act as natural pesticides by releasing biocidal molecules (biofumigation) from their roots, unlike intensive agriculture, which relies on chemical pesticides that release ammonia into the air.
• Weed suppression: Helps control weed growth by competing for resources.
• Aesthetic and ecological benefits: During flowering, mixed-species sowing creates colorful landscapes, while honey-producing plants attract beneficial insects such as bees.
The most used green manure plants belong to these categories:
• Legumes (clover, vetch, broad bean, sainfoin, protein pea) provide nitrogen through root symbiosis with nitrogen-fixing bacteria.
• Grasses (barley, rye, oats, fescue) and buckwheat help absorb nitrogen from the soil.
A good green manure practice involves selecting varieties with similar biological cycles to ensure uniform flowering. Proper shredding and drying of residues before burial maximizes the organic matter supply, which also depends on the carbon-to-nitrogen (C/N) ratio.
Following these simple principles, combined with precise planning, allows farms to enrich the soil with large quantities of high-quality organic matter. This enhances biological fertility, providing farmers with a more productive substrate for future crops. The careful selection of green manure composition ensures that the soil is well-prepared for the next crop, creating a more favorable growing environment right from the start.