Žemės dirbimo įtaka dirvos bendrajam poringumui kukurūzų pasėlyje

Abstract

The protection band of the plot was of 1 m width and that between replications of 9 m width. Soil displacement setting sorption method (pF) method. Soil displacement investigate using two kinds of devices – suction and pressure. Suction devices operating at 0 to 2.7–3.0 pF meanings, and pressure devices – to get higher values (Klute, 1986; Soil water retention..., 2002). Soil pore structure knowledge allows to predict water infiltration speed, accumulated in the soil available to plant, and the amount of water and soil aeration conditions. In the upper (5–10 cm) soil layer are biggest (0,416 m3 m-3) the total porosity determined using direct drilling in no-till soil, compared with convention ploughing. For the purposes of conventional tillage for 15–20 cm soil layer was observed in the general porosity increase, but not a substantial impact. Using shallow cultivation 30–35 cm soil layer determine total porosity growth (from 3 to 5 proc.) tendency. Soil porosity – one of the main indicators characterizing soil. Often not hard part of soil, but the soil porosity due to it’s suitability to grow agricultural plants. Soil porosity – soil in the volume of voids (%), per unit volume of soil. Soil voids may be filled by water or air. Solid fraction of soil distribution determine it’sporosity (Danielson, Sutherland, 1986). Analysis target: to determine the influence of soil tillage reduced of the soil general porosity. The soil has formed in the region of bottom moraine or bottom glacial formations, covered by glacial lacustrine sediments.The soil of the experimental field is Endohypogleyic-Eutric Planosol–PLe-gln-w (Buivydaitė ir kt., 2001). The field experiment was set up in 1988 in the then Lithuanian Academy of Agriculture’s Experimental Station. Prof. dr. A. Stancevičius was the initiator and leader of the experiment. At that time the experiment was conducted in the six-course crop rotation. Since 2001, the experiment has been modified by assoc. prof. dr. V. Bogužas by introducing direct drilling treatment and four-course crop rotation. The experiment is being continued. Primary soil tillage methods investigated: 1. Conventional ploughing at 23–25 cm depth (CP) (control treatment); 2. Shallow ploughing at 12–15 cm depth (SP); 3. Deep cultivation at 23–25 cm depth (DC); 4. Shallow cultivation at 12–15 cm depth (SC); 5. Not tilled soil (direct sowing) (NT). Crop rotation in the experiment: 1) spring rape ; 2) winter wheat ; 3) maize; 4) spring barley. The experiment involved 4 replications. Each crop was cultivated in 20 plots. The initial size of plots was 126 m 2 (14 x 9 m), and the size of record plots was 70 m 2 (10 x 7 m). The plots of the experimental treatments were laid out in a randomised order.