engleski

Soil resistance to penetration in different tillage methods

Increasing soil compaction has become a global problem due to the use of ever larger and heavier tractors and attachments, i.e. more intensive tillage and also tillage under unfavourable conditions. As a consequence, low or decreasing yields are obtained due to increased bulk density of the soil, which is also reflected in reduced infiltration and transmission of water into/through the soil, lower pipe drainage efficiency and crop rooting depth, higher incidence of plant diseases and reduced root efficiency. Aimed at determining the optimal tillage system for the region, five-year penetration resistance measurements, among others, were carried out on pseudogley of the trial field "Freivogel’s Hill" near Daruvar in central Croatia. The trial included the following treatments: Standard plot, black fallow, ploughed up/down the slope; 2. Conventional ploughing up/down the slope; 3. No-tillage; 4. Conventional ploughing across the slope; 5. Very deep ploughing across the slope (50 cm); and 6. Subsoiling to the depth of 60 cm + conventional ploughing across the slope. Crops were sown in the following crop rotation: 1994/95 - maize, 1995/96 - soybean, 1996/97 - winter wheat, 1997/98 - oil rape, and 1998/99 - spring barley + soybean. Measurements of soil resistance to penetration to the depth of 50 cm in four repetition, as the principal parameter of soil compaction, were carried out continuously parallel to the plant cover growth and application of appropriate agricultural practices using The Bush Soil Recording Penetrometer. At the same time, samples were taken of the soil while in disrupted state in order to determine its moisture. The five-year investigations point to the conclusion that the soil resistance to penetration is predominantly influenced by the effective state of the plant cover development, actual soil moisture and the tillage system applied. The lowest penetration resistance results in all trial treatments were recorded in first measurements, immediately after the application of tilling practices. In treatments involving deep practices (very deep ploughing and subsoiling) penetration resistance values were constant to the measurement depth whereas an increase was recorded in penetration resistance below the ploughing depth in treatments with conventional ploughing to the depth of 30 cm. Soil resistance to penetration recorded in the winter period was expressly low, one might say it was practically non-existent. The overall lowest values of soil resistance to penetration throughout the investigation period were recorded in treatments with very deep ploughing and subsoiling or ploughing across the slope, while the highest penetration resistance was determined in the no-tillage treatment, as a consequence of the tillage method applied in this treatment.

erosion by water; USLE; erosional drift; soil tillage; pseudogley

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