Physical assessment of a Mollisol under agroecological managements at Quillota valley. Mediterranean Central Chile

Abstract

A number of agroecological practices have been proposed for assessing soil quality. Several physical soil properties have been shown to be important for determining soil quality by using the sustainability index (SI) and the cumulative rating approach. The main aim of the study was to determine the effects of different agroecological managements on the physical properties of a Mollisol in the Mediterranean central Chile. In addition, some physical properties were selected to compare the soil quality among different agroecological management practices and highly mechanized intensive systems by using the SI and cumulative rating approaches. An experimental field was defined in an area of 3.5 ha in 2014. Four sites with different agroecological practices were selected in 2019 to assess soil physical properties: rainfed Mediterranean annual prairie - no tillage (1-S), irrigated perennial prairie with deep-root species - no tillage (2-N), irrigated annual and perennial prairie - conventional tillage (4-S), irrigated vegetables and flowers - minimum tillage (4-N); an avocado orchard with traditional management was used as the control. Soil organic carbon and the following soil physical properties were selected to assess SI and CR: bulk density, total porosity, void ratio, air capacity, fast-drainage pores, relative field capacity, hydraulic conductivity, structural stability index and unavailable water pores. The applicability of the selected physical indicators to the SIs of agroecological management practices compared with the control was demonstrated. The cumulative rating index (CR) for each land use showed that all agroecological practices constituted sustainable soil management (25≤CR<30), whereas the avocado orchard showed the least sustainable management (30≤CR<40), and a change in soil use is recommended.

Challenges for agroecology development for the building of sustainable agri-food systems

“…They note that the greater adoption of intercropping in European agriculture requires solving technical, societal and knowledge challenges in crop production, understanding the long-term effects of diversification, and identifying and eliminating lock-ins and barriers against diversified cropping in agricultural systems. Casanova et al (2020) carried out a soil sampling survey comparing soils under industrial avocado production to those managed with agroecological practices. Using cumulative sustainability ratings for each land use, they showed that all agroecological practices constituted sustainable soil management although with high organic input requirements, while industrial avocado production was the least sustainable soil management to the extent that the authors recommended a change in land use.…”