Efekat nastiranja i đubrenja na prinos i kvalitet kupusa | Effect of mulching and fertilizing on yield and quality of cabbage | Ефекат настирања и ђубрења на принос и квалитет купуса

Cabbage is one of the most important vegetable crop from a nutritional and economic point of view. For the market needs, it is produced during all year in the open field and in a greenhouses. Cabbage is produced in early and mid-early open field production with soil mulched with polyethylene sheet. Mulching is an agrotechnical measure that is wide-spread in the production of vegetables, producing significant results in the production of almost all crops. Fertilization is a very important agrotechnical measure in cabbage production. The formation of high biological and economic yield requires a large amount of affordable soil nutrients, and fertilization has the most significant impact on the amount of affordable soil nutrients in all known production systems. In 2010, 2012 and 2013 was examined influence of soil mulching with black polyethylene film and fertilizing with organic and mineral fertilizers on yield and quality of cabbage. In order to solve this task, a survey was conducted on the experimental field of Agricultural Extension Service Sombor at the Toplana (heating plant) location. The two factor experiment was set up in split-plot method in four repetitions in 2010, and in three repetitions in 2012 and 2013. The main plots (factor A) consist (include) experiment without mulching (control) and experiment with mulching with a black polyethylene sheet. The sub parcels (factor B) consist control without fertlizing and eight fertilizer variants. Soil mulching with black polyethilene sheet significantly increased head yield of mid early cabbage, biological yield, the mass of the head and the amount of harvesting residues. Fertilization significantly increased cabbage head yield, biological yield of cabbage and average head mass. Increasing amounts of N linearly increase the head yield, biological yield, and cabbage head mass with statistically significant correlation coefficients. The highest average head yield was obtained on the SKS+N55P55K105 variant (51.63 t/ha) and the lowest on the control without fertilization (30.74 t/ha). The highest average head mass was achieved on the SKS+N55P55K105 variant (1.44 kg) and the lowest on the control without fertilization (0.70 kg). Mulching didn’t affect on harvest index value, whereby the same harvest index (0.67) being achieved on both treatments. Fertilization and mulching significantly affect the amount of N and P2O5 adopted by head yield, whereas in the case of K2O the impact of mulching wasn’t statistically significant. During the three-year study, cabbage average adopted 16.88 kg N, 5.78 kg P2O5 и 18.88 kg K2O with 10 t of head yield. On mulching treatment, the partial balance of N, P2O5 и K2O was higher compared to the control without mulching. The average value of the partial balance N was 0.72, P2O5 0.21 и K2O 0.74, indicating that more nutrients were applied through the fertilizer than the cabbage crop had received in the head yield. On the treatment with mulching, the average dry matter content was 1.07% higher than treatment without mulching, but the increase wasn’t statistically significant. The highest dry matter content in the three-year research was achieved on variant N55P55K105 (7.98%), while the lowest content was measured on the control without fertilization (7.24%). Mulching significantly increased the total nitrogen and phosphorus content in the dry matter of head leaves, while the potassium content was significantly higher at the treatment without mulching. At the mulching treatment the content of trace elements (Zn, Mn, Cu, and Fe) in the dry matter of head leaves was higher than treatment without mulching. Mulching significantly increased the nitrate content in the leaves of head. On the treatment without mulching, the lowest nitrate content was recorded on the control without fertilization. The average value of nitrate content achieved on variants where mineral fertilizers were applied was between the values of nitrate content on the control and variants where organic fertilizers were applied. The average content of Cd in the dry matter of head leaves was 0.013 ppb, with a higher Cd content for 0.002 ppb was observed at the mulching treatment.