THE BENEFITS OF DIRECT DRILLING ON A FARM IN THE ALENTEJO (PORTUGAL)

Abstract

In the present work it is intended to show the positive modifications in a farm located in the Alentejo region in the south of Portugal after 4 years of direct drilling system implantation. The soils in the study area are Luvisols, characterized by a poor structure, bad internal drainage and cumulative negative effects of conventional soil tillage used before direct drilling. The effects after 4 years of direct drilling resulted in reduction of erosion and soil compaction and improved physical, chemical and biological characteristics of the soil mainly by: increment of biological porosity and soil structural improvement and stability. The improved soil conditions allowed a deeper root growth and higher infiltration rate and a better soil bearing capacity. This has improved the opportunity for applying nitrogen and herbicides. All together enhanced crop growth. Additionally it was registered a significant reduction not only in the number of tractors and soil tillage equipment in the farm, but also in the maintenance and repair costs and in labor costs. Pulses (chickpea and peas) where introduced in the rotation with winter cereals, and the farm adopted other practices with direct drill such as the maintenance of straw at the soil surface and the utilization of special equipment for soil conservation (lighter tractors with double rear tires and straw dispersion equipment in the harvester). Despite the complete change regarding the soil management system (change of the whole farm to direct drilling), it was possible to maintain the perfect integration of animal (sheep) and crop production in the farming system, using only partially crop residues for animal feeding.