Effects of compost maturity on growth of komatsuna (brassica rapa var. pervidis) in neubauer's pot

Abstract

Growth of komatsuna (Brassica Rapa var. pervidis) was studied on Fujimi sandy soil treated with garbage composts of different maturity using Neubauer's pot under artificial light and controlled temperature. Inhibitory effect on komatsuna growth was evaluated by comparing the growth in the compost treatments with that in inorganic nutrient treatments with the same amount of inorganic nitrogen as in the composts. Under a loading of 10 g dry weight per pot, which is equivalent to 10 dry ton of compost per 1 ha in land application, the treatment with immature composts resulted in considerably lower yields compared with the controls. Inhibitory effect was observed especially in the early stages of growth. The well-mature composts gave higher or equal yields compared with the controls. On the other hand, with a loading of 20 g per pot, all the compost treatments resulted in lower yields than those of the controls regardless of compost maturity. The inhibitory effect was mainly observed in the later stages of growth. It was also shown that komatsuna took up nutrients from the water-soluble compounds in the composts during 2 weeks.