Intensive fodder production under irrigated condition in partial shade

Abstract

A field experiment was conducted in the upland coconut gardens of Instructional Farm, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala, to study the potential of intensive fodder cultivation under shaded condition. The influence of irrigation, FYM and fertilizers on the yield and quality of fodder and the effect of grass cultivation on the physico-chemical properties of soil were studied. 'The economics of irrigated fodder production was also worked out. The investigation was conducted for a period of one year from July 1998 to June 1999. The results revealed that irrigation at 30 and 45 mm CPE improved the growth parameters like plant height, tiller number uu', Leaf: Stem ratio and Leaf Area Index of congosignal and gave higher green fodder as well as dry fodder yields. Application of 7.5 t ha" of FYM increased the plant height,tiller number hiWl and Leaf Area Index. The uptake of plant nutrients viz., N, P, K, Ca and Mg by congosignal was favoured by irrigation. Application of FYM was not found to enhance the nutrient uptake, but, chemical fertilizers improved the uptake of nutrients by congo signal. Soil physical properties like bulk density, water holding capacity and porosity were improved by grass cultivation. Irrigation and application of FYM and fertilizers improved the soil physical properties. Irrigation and FYM application increased the soil organic carbon content. Available P and K status of the soil was improved by irrigation, while available N status remained almost unchanged. FYM or fertilizer application did not change the available N, P and K content of soil upto 7.5 t ha-I ofFYM and 150 : 50 : 50 kg NPK ha-I. Irrigation improved the fodder quality in terms of crude protein content. There was no improvement in the quality of fodder by FYM or fertilizer application at the recommended doses. Irrigated congosignal crop depleted more moisture from the top 0 - 30 cm layer of soil. The rainfed crop extracted more water from deeper layers than the irrigated crop. Root growth of congosignal was favoured by irrigation. While considering the economics of fodder cultivation, 45 mm CPE irrigation treatment was found to be the best, when compared to treatments involving 30 and 60 mm CPE irrigation and the rainfed control. Highest benefit : cost ratio was recorded for the treatment combination : irrigation at 45 mm CPE and recommended doses of manures and fertilizers (FYM @ 5.0 t ha-I and NPK @ 150 : 50 50 kg ha-I) when congo signal was grown as an intercrop in coconut garden.