Žemės dirbimo intensyvumo ir šiaudų įterpimo įtaka dirvožemio agrocheminėms savybėms

Abstract

Soil tillage is one of energy and time-consuming activities in husbandry. Objective of the research - to evaluate effect of direct drilling, reduced tillage and straw on agrochemical soil properties. Stationary two factor field experiment was established in Experimental Station of Aleksandras Stulginskis University in 1999. Treatments: Factor A - straw incorporation: without straw (-S); with straw (+S). Factor B- soil tillage systems: deep ploughing at 23-25 cm depth in autumn (GA); shallow ploughing at 10-12 cm depth in autumn (SA); shallow loosening at 8-10 cm depth in autumn (KL); shallow loosening with rotary cultivator at 5-6 cm depth before sowing (RK); shallow incorporation of green manure with rotary cultivator at 5-6 cm depth before sowing (ZTRK); no tillage, direct sowing (ND). It was established that long-term use of straw increases the amount of soil pH, humus and nitrogen. The amount of humus and nitrogen is mostly increased by shallow loosening with rotary cultivator (RK), shallow incorporation of green manure by this cultivator in spring (ZTRK) and direct sowing (ND). The greatest amount of humus was found in the topsoil layer of these treatments. Direct sowing (ND), shallow loosening with rotary cultivator (RK) and shallow incorporation of green manure by this cultivator (ZTRK) especially raises the amount of available phosphorus, potassium, humus and nitrogen in 0-10 cm soil layer. Direct sowing (ND) and shallow incorporation of green manure by this cultivator (ZTRK) raises the amount of humus in 10-20 cm soil layer. Shallow loosening with rotary cultivator before sowing (RK), shallow incorporation of green manure by this cultivator in spring (ZTRK) and direct drilling (ND) stimulate the accumulation of available phosphorus and potassium in the topsoil. The amount of available phosphorus in 10-20 cm soil layer is lower by 31.0-32.5 % than in the topsoil and the amount of available phophorus in 10-20 cm soil llayer is lower by 31.0-32.5%