No abstract

Winter cover crops may provide different environmental benefits in agricultural systems. The aim of this study was to determine the effect of cover crops used as green manure on the soil nitrogen (N) budget and yield of silage maize (Zea mays L.). A field experiment was conducted between 2011 and 2013 at three locations in Vojvodina Province, Serbia. It compared common vetch (Vicia sativa L.), triticale (× Triticosecale Wittm. ex A. Camus), their mixture grown as cover crops, N fertilisation at two doses (N1 and N2), and an unfertilised fallow as a control. Cover crops were sown in autumn 2011 and 2012 and were ploughed in during May of the year after which silage maize was sown. Results show that the ability of cover crops to provide benefit for a subsequent crop is highly related to weather conditions, mainly precipitation. The two years of the study experienced completely different weather conditions, showing two aspects of how cover crops can affect subsequent crop yield and amount of N left in the soil. In 2012, the N budget was higher in all three cover crops at all locations than N1 and the control because of unfavourable weather conditions for mineralisation of organic matter. However, the cover crops had a negative effect on silage maize yield. In 2013 (an average year), the N budget was significantly higher after cover crops, and was followed by a higher yield of silage maize. Based on the 2-year average, the highest value of apparent N remaining in the soil was recorded in the mixture treatment (288.13 kg N ha–1); treatments with vetch and triticale had approximately equal values (272.17 and 272.71 kg N ha–1). The N fertilisation treatments and the control had significantly lower average values of residual N.

The objective of this research was to quantify the effect of the application of organic fertilizers: farmyard manure, vermicompost, spent mushroom compost, under two different ground cover management systems (black polyethylene and wheat straw mulch) on soil nutrient levels and strawberry yield during a two-year production cycle. The application of organic fertilizers, in the amounts equivalent to 170 kg ha -1 N, had the greatest impact on the concentration of available phosphorus, which was significantly higher on fertilized plots than on the control even two years after the application. The plots fertilized with farmyard manure and mushroom compost had higher concentrations of available potassium than the control, while the application of vermicompost did not affect the concentration of available potassium in the soil. The application of composts did not affect the concentration of available microelements in the soil, while the concentrations of Fe, Zn and Cu in the year of the organic fertilizers application were significantly higher on farmyard manure fertilized plots than on the control. The application of all three organic fertilizers had a significant effect on the mineral N concentration in the soil only in the year of the application and the following spring. However, the plots covered with polyethylene mulch had a higher mineral N concentration than the control at all sampling times. The concentration of available microelements was significantly higher in soil covered with black polyethylene mulch than in soil covered with straw mulch. Preplant application of organic fertilizers led to increase of yield, ranging from 14.3% in vermicompost treatmet to 17.3% in the farmyard manure treatment in relation to the control, only in the 1 st fruiting year. However, the application of polyethylene mulch facilitated a higher strawberry yield than straw mulch in both fruiting years.

No abstract

In order to achieve a high yield and quality of apple fruit, more effective ways of fertilization are required in the modern, high density apple orchards. The objective of this research was to determine the efficiency (partial nutrient balance, PNB) of different methods (foliar and fertrigation) and forms (chelates and salts) of microelements application in relation to the levels of N fertilization in apple orchard cultivar (‘Golden Delicious’). The combined effects of these fertilizers on the number of apple fruits per tree and on the yield per tree were also studied. Foliar application of Mn, Zn and Fe had significantly higher partial nutrient balance values compared to the soil application in both years of the experiment. However, most of the PNB values were below 10% indicating relatively low efficiency of the applied fertilizers with microelements.