Effect of tillage systems and P-fertilization on soil physical and chemical properties, crop yield and nutrient uptake

Data from a long-term fertilization trial at the Institute for Crop and Soil Science in Braunschweig, Germany were used to evaluate the influence of tillage systems and phosphorus (P) fertilization on the physical and chemical properties of soil, P accumulation in soils, yield of various crops, and P uptake. The trial was set up in 1985. In 1998 two tillage systems, conventional and conservation, and three different fertilizer regimes were implemented. The three fertilizer regimes were (i) nitrogen and potassium, (ii) nitrogen, potassium and farmyard manure, and (iii) nitrogen, potassium, phosphorus and farmyard manure. Results from 1998 onwards are presented. Six and 8 years after implementing the two different tillage systems, the conservation tillage management resulted in a better pore connectivity and a higher saturated hydraulic conductivity than the conventional system. Generally, the soil organic matter (SOM) contents increased in all treatments from 1998, and were higher under conservation than under conventional tillage. The yield was not significantly affected by the tillage system. Mineral P-fertilization at a rate of 40 kg ha(-1) annually resulted in a build-up of plant-available P in the top soil compared with non-fertilized plots, but in general did not increase P uptake. While the reduction in tillage intensity affected soil properties, it had very limited effects on yield and nutrient uptake. (C) 2008 Published by Elsevier B.V.