Efficiency of slow-acting fertilizer in the integrated cultivation of chinese cabbage

Abstract

The study aimed to assess the suitability of slow-acting fertilizer in cultivation of Chinese cabbage in the integrated production system. The assumed objective was realized on the basis of a strict field experiment set up on the soil with granulometric composition of medium loam. The test plant was Chinese cabbage (Brassica rapa L.), ‘Parkin F1’ cv. The experiment was set up on 17.08.2011 and the plants were harvested on 08.10.2011. The experimental factor was diversified fertilization. The cultivation and protection of the plants were conducted on the basis of methodology of Chinese cabbage integrated production approved by the Main Inspector for Plant Protection and Seed Science. Traditional fertilizers (triple superphosphate, potassium salt and ammonium nitrate) and NPKCaMg (18-05-10-4-2) multi-component fertilizer with nutrient slow-release were applied. The experiment comprised 8 fertilization variants and the control treatment. Doses of phosphorus and potassium, meeting the plants requirements at assumed yield amount, were applied in all fertilization variants. Nitrogen fertilization on subsequent objects differed both with the form and quantity of applied element. On the basis of the results obtained in conducted experiments, the indices showing nitrogen fertilization efficiency were computed: agronomic efficiency, partial factor productivity, physiological efficiency, nitrogen recovery efficiency and removal efficiency. Fertilization significantly modified the quantity of obtained yield. On the control, without mineral fertilization, the crop yield was 44.22 Mg ha. The largest yield, 120.7 Mg ha, was obtained on the object with an admixture of 400 kg of slow-acting fertilizer, 89 kg of triple superphosphate and 177 kg of potassium salt. The best optimal values of fertilization efficiency were obtained in the objects where 400 and 500 kg ha of slow-acting fertilizer and full doses of phosphorus and potassium were applied. Computed indices of fertilization efficiency indicate that optimization of fertilization using slow-acting fertilizer, particularly in conditions of intensive cultivation, may improve fertilization efficiency several-fold in comparison with integrated production methods using traditional fertilizers. Results of conducted experiments show that optimization of fertilization in conditions of intensive production may enhance fertilizer nitrogen uptake by 50 % at maintained high crop yields, which greatly improves economic effectiveness of production and reduces the amount of biogens dispersed in the environment.