Response of crops yield to long-term reduced soil tillage and direct sowing

Abstract

During 15 year period cumulative wheat grain yield in plots with reduced tillage was less by 2.11-2.89 t ha-1 than that in conventionally ploughed plots. Significant winter wheat grain yield decrease took place in 2013 where deep chiselling was applied and in 2014 where shallow ploughing was used. Response of wheat grain yield to application of direct drilling was positive. Direct sowing had no negative effect on sugar beet yield only during period 2001-2003. Cumulative sugar beet yield from 2001 to 2007 was less by 18.6 t ha-1. Shallow ploughing, deep and shallow chiselling had no significant influence on sugar beet cumulative yield as compared with conventional ploughing. Maize was sensitive to application of direct drilling. Cumulative maize grain yield during period 2008-2015 was less where reduced soil tillage and direct sowing were used than that where plots were conventionally ploughed. Significant maize yield reduction by application of all reduced tillage and direct sowing treatments took place in 2012. Cumulative spring barley grain yield during 15 year period in plots with reduced tillage application was similar to that where conventional ploughing was used. In opposite, direct sowing reduced cumulative barley grain yield starting from year 2005. Here cumulative yield reduction within period 2001-2015 was 3.42 t ha-1. Many short-term field experiments worldwide are done to investigate reduced soil tillage but only limited number long-term ones. The effect of short- term and long-term reduced tillage and direct sowing on crops can be different. The aim of our investigation was to study response of several crops yield within 15 years period to application of long-term reduced soil tillage and direct sowing. Field experiment was set up at Experimental Station of Aleksandras Stulginskis University (at that time Lithuanian Agricultural Academy) in 1988 and modified in 2001. Soil of the experimental site – Endohypogleyic-Eutric Planosol – Ple-gln-w. Soil texture – medium loam on sandy loam over the moraine clay. The effect of following five treatments was investigated: conventional ploughing at 23-25 cm depth (CP), shallow ploughing at 12-14 cm depth (SP), deep chiselling at 23-25 cm depth (DC), shallow chiselling at 12-14 cm depth (SC), direct sowing (DS). Crop rotation in the experiment: 1) spring rape, 2) spring wheat (2001-2003) and winter wheat (from 2004), 3) sugar beet (2001-2007) and maize (from 2008), 4) spring barley. During fifteen year period (2001-2015) cumulative spring rape seed yield was higher when reduced tillage and direct sowing were applied as compared with that where soil was conventionally ploughed. This yield increase was not significant – in average up to 0.10 t ha-1 per year. Reduced tillage had no negative influence on cumulative spring and winter wheat yield until 2010.