Evaluation of organic Substrates for wheat production under rainfed conditions

A study was carried out to evaluate the effect of different organic amendments and bio-fertilisers on organic wheat crop at National Agricultural Research Center (NARC), Islamabad during the year 2008-2009. Randomised Complete Block Design (RCBD) with four replications was used. The soil at NARC is slightly alkaline. Organic matter ranges from 0.31-2.50 % in the surface soils and 0.15-2.50 % in sub-soils. Most soils at NARC have low soil organic matter content. The treatments included (a) organic fertilizers 3: 16:1.5 (N:P:K), 15kg N, 85kg P/sub 2/O/sub 5/and 7kg K per acre),(b) organic fertilizers (NPK),15kg N, 85kg P/sub 2/O/sub 5/and 7gK+ Humic acid (8/acre as basel dose and foliar spray), (c) compost (well decomposed and fermented with yeast mixed with molasses) 1000kg/acre (1.5% N,1.2% P/sub 2/ O/sub 5/ and 0.8% K), (d) a control. Different organic products including bio-trace, humic acid (granulated form, i.e. lignatic coal treated with 10% potassium hydroxide) and humic acid alkaline solution in water were applied in the form of foliar spray on the crop (treatments 1 and 3) at six leaves stage, after 1.5 months and at spike emergence stage. The use of organic fertiliser with compost alone or in combination increased growth parameters as well as wheat yield, with maximum biomass (5,788kg/ha). Minimum biomass was recorded in the control treatment. The soil chemical, physical and biological properties were improved with addition of all types of organic substrates. The soil quality relates with its characteristics and microbial dynamism. (author)