Changes in soil properties under high- and low-input cropping systems in Lithuania

Abstract. To determine the effects of low-input agriculture on soil properties, we compared several forms of arable land management in a rotation experiment lasting 8 years on a Cambisol in Lithuania. Conventional arable cropping with applications of inorganic fertilizers increased the potassium (K) status of the soil, but resulted in losses of nitrogen (N) from the soil by mineralization and leaching. With ley–arable integrated cropping, a similar fertilizer regime based on farmyard manure (FYM) augmented with inorganic fertilizers increased the phosphorus (P), K, organic matter and N in the soil, as well as increasing N loss by leaching. These two high-input regimes were compared to three systems with less or no input. A reference treatment with no input, which produced small crop yields, maintained its nutrient status and organic matter. An organic regime receiving FYM and green manure lost only P, but maintained its K and N status, while a second organic regime in which the FYM was replaced by composted sewage maintained its fertility. The microbial activity varied somewhat from treatment to treatment, with the largest numbers of almost all groups of microorganisms in the reference treatment. All treatments led to decreases in fulvic acid, and the soil managed conventionally lost humic acid, too. The content of humic acid increased in the treatments where FYM was applied and in the reference soil, and the fraction bound to calcium increased in the integrated and the first organic treatments. The soil structures under the integrated cropping and second organic regime were the most stable. Of the low-input systems, the second organic regime seemed the most sustainable.