Perspectives for a Sustainable Production of Row Crops in Systems of Minimised Tillage—A Special Focus on Sunflower Cropping in Western Siberia

Abstract

Sunflower and corn are widely spread row crops in the continental agricultural steppes of America and Eurasia. Sunflower, in particular, is more demanding than other common regional crops regarding the preparation of the soil and nutrient supply. Due to the high profits in sunflower farming, significant investments have been made into intensive mechanical soil preparation and plant nutrition. Due to the open nature of row crops until late in the vegetation season, the soil is exposed to wind and water erosion for long periods of time. Spreading large amounts of required nutrients as mineral fertiliser is only practical to a limited extent due to low precipitation and its uneven temporal distribution. Deep soil tillage in strips with simultaneous fertiliser placement in deeper soil layers represents an economically and agriculturally sound alternative to full-area loosening. The soil is cleared in strips from any harvest residues. This procedure improves germination and emergence conditions in the cold spring. In the deeply loosened strips, plant roots grow more quickly towards the fertiliser depot worked into the soil. The targeted deep growth helps plants to open up more soil water resources and survive drought periods. Traction per unit area and therefore fuel, time and costs can be saved because the soil is loosened in strips only. The agricultural and economic profitability of the strip-till method for sunflower and corn was tested in a dry steppe location for several years as a part of the KULUNDA research project. Optimum values for the working depth and amount of fertiliser were determined for the location.