engleski

Effect of composted manure on plant growth in horticultural container media

Given that it has similar physical and chemical properties, the compost could be used as a cheaper substitute for a commercial substrate. However, some limiting factors can occur in the compost (high salt and high pH value). In order to determine the correct replacement of the substrate for growing seedlings of vegetables, investigation was conducted on two different composts produced from chicken and pig manure. Both the compost had a high salt concentration and basic nutrients, while composted chicken manure had a high pH value, and pig manure had a lower pH. Three different mixtures were made from each of the composts with the following contents: a commercial substrate as a control, compost alone, and mixtures of 25, 50 and 75% compost or commercial substrate. Testing was conducted on lettuce (Lactuca sativa L.) as a culture very sensitive to increased salt concentration (> 2 dS m-1). We observed the following parameters of growth of lettuce: the number of seedlings, height, weight and seedling leaf area and dry matter content. pH values of components were ranging from 6, 27 on commercial substrate to the 8, 15 in chicken compost, or 5, 55 in pig compost, and EC values from 0, 74 in commercial substrate to 14, 83 in poultry compost, and 8, 76 in pig compost. Effect of salt concentration on lettuce seed germination is already visible at 50% of composted manure. Based on the results we can conclude that only the substrate in which the proportion of compost was 25% had an optimum pH value and gave results similar to control. A higher proportion of compost increased the concentration of salts to toxic values. However, mixture of more than 25% compost with high EC and pH value may have depressive effect and reduce the growth of plants. This compost could possibly be used as a good fertilizer, but in limited quantities.

substrate for growing seedlings ; composted poultry manure ; composted pig manure ; lettuce

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