Soil hydraulic arrangement and agro-ecological practices in organic rotations: effects on crop performance, soil properties and carbon balance

Abstract

ABSTRACT Extreme climate events have increased in recent years, leading to huge losses of agricultural products. A field study of a two-year organic horticultural rotation (2015–16 and 2016–17) was conducted to evaluate the effects of soil hydraulic arrangement and cover crops management on cash crops productivity, soil carbon (C) and nitrogen (N) sequestration, greenhouse gas (GHG) emissions and C balance. The experiment consisted of two simultaneous rotation systems, a cauliflower-tomato rotation on raised beds and a zucchini-lettuce one on flat strips between them, combined with cover crops as living mulch or break crops. The results pointed out that the use of proper hydraulic arrangements may partially reduce the exposure of crops to extreme climate events, like heavy rains and floods, allowing the preservation of soil fertility. The cover crops increased the yields and enhanced the soil nutrient pools. Our study showed the important role of cover crops since the soil C stock values were significantly higher when they were used in the rotations. The analysis of the GHG emissions, C balance and C efficiency revealed that combining agro-ecological and conservation practices can improve environmental sustainability in organic farming in the Mediterranean area, allowing farmers to maintain/increase their agricultural systems sustainability.