Sustainable tillage: results from long-term field experiments on Cambisol.

Abstract

The goal of this paper is to present the newly obtained data on the changes in soil physical and chemical properties, weed incidence and crop yielding capacity from the long-term tillage experiments, lasting for more than 10 successive years, carried out in the middle lowland of Lithuania on an EndocalcariEpihypogleyic Cambisol (CMg-p-w-can), at the Institute of Agriculture, Lithuanian Research Centre for Agriculture and Forestry. It was revealed that conventional tillage (CT) produced the best soil physical properties (the lowest bulk density, cone penetration resistance, and the highest air permeability). Significantly worse soil physical properties were registered after no-tillage (nT) application, while under global warming conditions the application of the NT system may be the right measure to preserve soil moisture at the early stage of crop development. NT caused higher soil total N, available P2O5 and K2O stratification in the soil during crop rotation period compared to reduced tillage (RT) and CT. effectiveness of moderate rate of NPK fertilisers on loam decreased in this order according to tillage intensity: CT → RT → nT, while on sandy loam the effectiveness of moderate rate of nPK fertilisers tended to increase in the same tillage order. Application of high rate of fertilisers on loam was ineffective in CT and RT systems, but in NT system this measure increased metabolizable energy (ME) by 16% compared to moderately fertilised treatments. efficacy of high rate of fertilisers on sandy loam was not significant in all tillage systems investigated compared to moderately fertilised treatments. The heavier weeds population, the more favourable conditions for herbicide action were created. Therefore a combination of NT and glyphosate application on sandy loam was less effective than mechanical weed control in CT and RT. In CT treatment the changes in weed incidence were irregular in a 4-course crop rotation in the experiment set up in 1956. Application of both RT systems tended to decrease weed mass during the experimental period. nT application produced significantly lesser amount of Me during an 8-course crop rotation, compared to CT and RT on both loam and sandy loam.