Minimum tillage and vegetable crop rotation

Abstract

Soil quality improvement by reducing soil tillage is one tool of sustainable agriculture. Covers crops left on soil surface prevent soil erosion, reduces evapotranspiration and weeds, and improves soil infi ltration; key factors for a successful vegetable production on heavy clay soils. The objective of this research was to evaluate the effect of cover crops plus ridge tillage on soil water content, soil, physico-chemical and biological properties and on vegetable yield. In 2005 at INIA Las Brujas Research Station was established a fi eld experiment on a Typic Argiudoll soil, of silty clay loam texture with a 3% slope. Conventional treatment with fallow periods was compared with sustainable treatment included cover crops and minimum tillage. Onion ( Allium cepa L.), cabagge ( Brassica oleracea, Capitata group), carrot ( Daucus carota ), sweet potato ( Ipomoea batata ) and squash ( Cucurbita moschata x C. maxima ) crops were included in the study. Black oat ( Avena strigosa ), foxtail millet ( Setaria italica ) and forage sorghum ( Sorghum sudanense x S. bicolor ) were the cover crops. Soil water content was measured by time domain refl ectometry on soil surface and by neutron probe in depth. Weed population was evaluated by number and dry weight. Soil biological activity was determined by soil respiration. Weed population and weight of weeds were reduced with minimum tillage as compared to conventional treatment. Soil water content was higher at certain periods on minimum tillage and biological activity was better on minimum tillage. Vegetable crop yields were similar on both treatments.