hrvatski

Zaštita od erozije - ključna uloga obrade tla u aktualnim i izmjenjenim klimatskim prilikama

The impending climatic changes call for reconsideration of soil tillage practices in agriculture so as to provide adequate yields of crops on the one side, and soil and water protection from all damages, particularly erosion, on the other side, and thus contribute to the stability of the agroecosystem. This especially applies to soil tillage, as the oldest and most important soil management practice in plant production. In addition to these current objectives of tillage, tillage as a soil management practice is about to obtain a new task. Namely, all economic branches will have to reduce the emission of CO2 , and in agriculture this task will be assigned to soil tillage, that is, to the management of crop residues. The tillage of tomorrow will have to be conceived so as to retain carbon from soil residues in the soil (and/or on the soil) and in this way reduce the aerobic processes of mineralization of soil organic matter as well as CO2 emission. The protective retention of plant residues on soil surface - mulch, retains carbon in the soil and directs it into SOC (Soil Organic Carbon) - humus reserves. Changes in climatic conditions in both possible directions - increase or decrease of annual precipitation and or mean annual temperature will actualize the issue of soil conservation by tillage system. An important theoretical and practical question also in the current climatic conditions is whether and to which extent soil erosion by water may be reduced by tillage and by "directing" carbon. To estimate the effect of the current climatic conditions, erosional drift was measured on stagnogley of sloping terrain in the Daruvar area in five different tillage variants and a no-tillage variant, in which crop residues were left on soil surface, in the soil rotation: maize-soybean-winter wheat. In the three-year investigation period, the highest erosion was recorded in the standard variant according to USLE - black fallow (tilled but unsown soil). In this variant, the average annual soil loss amounted to 114 tons per hectare, almost ten times as much as soil loss tolerant - T, according to USLE. In such agroecological conditions, the highest soil loss was recorded in maize production, followed by soybean, while the smallest loss occurred in winter wheat. In the current climatic conditions, an average loss of 0.55 to 0.95 cm of the plough-layer thickness was recorded in the standard variant, which means that the entire plough-layer would be removed in a period of 26 to 45 years. Vegetation cover provided by the crop and contour tillage reduce erosion. If contour tillage, which we recommend for the zone of stagnogley and other erodible soils, were applied, the soil could be preserved for the next several centuries, and in the case of subsoiling for more than a millennium. No-tillage is also an efficient method of soil protection from erosion. Since wide-row plantations are grown in this country (vineyards) on considerably steeper slopes that those used in our investigations, it is evident that the current soil tillage practice needs to be reconsidered and greatly corrected.

obrada tla; erozija; klima; oborine; održivi razvoj

nije evidentirano