Covering Tree Line with Black Poly Ethylene Sheets for Composting Fresh Animal Manures Reduces Weeds and Improves Tree Growth in Newly Established Orchards

Abstract

Three field experiments were carried out over two growing seasons to evaluate the response of weeds and the volume of fruit trees; peach, pear and olive to composting of manures at 10 kg·m^-2. Planting holes were prepared early January. Animal manures from different sources; broiler, cow, layer and sheep were mixed in the top 20-cm of the soil surface over a 40-cm band X 2.5m row per treatment in the planting row then either non covered or covered with black polyethylene (BPE) sheets for six weeks or for the period from January to October. Trees were then planted late February. The same treatments were repeated in November of the next year. Weeds were significantly reduced and fruit trees were significantly larger in the treatments with manures in the BPE-covered treatments as compared to the non-covered treatment. Perennials; Cynodon dactylon (L.) Pers. and Cardaria draba L. in addition to Convolvulus arvensis L. and Sorghum halepense (L.) Pers. tolerated the composting process. Most annual weeds did not appear in composted manure subplots. Main annual weeds included; Amaranthus blitoides S. Wats. A. garacilis Desf. Sinapis arvensis L. Chenpodium album L. in addition to some weeds species belonging to Leguminosae and Caryphyllaceae.