Soil temperature and moisture characteristics as influenced by inter-cropping of fodder crops in coconut garden

Abstract

An investigation was undertaken to study the effect of fodder grasses grown as inter crop in coconut garden on the soil characteristics. The observations were carried out from the already laid out experimental plot in the farm area of college of Agriculture. The layout was in randomised block design with six treatments and four replications. The treatments included guinea grass, congo, signal grass, setaria grass, molassess grass, hybrid napier and contrest. Soil samples were collected from two depths namely 15 cm and 30 cm from the surface. The samples were collected during March-April, July-August and December-January. The soil analysis was done for moisture, porosity, bulkdensity, particle density and water holding capacity. The infiltration rate and hydraulic conductivity were carried out at the close of the experiment. Chemical analysis was done for nitrogen, phosphorous, potassium, calcium and magnesium. The effect of growing fodder crops on soil moisture content was not significant. The thick canopy of guinea and congosignal grass could retain moisture in the field. The water holding capacity in the control plot was less than the fodder plot. So the competition for water would be minimum for coconut and fodder crops. The soil moisture was negatively correlated with soil temperature. Setaria and molasses grass could conserve moisture on the surface while other grasses could retain moisture on the subsurface layer. Fodder grass roots improved the structure of the soil. Bulk density values were reduced. The changes on particle density and porosity values were negligible. The hydraulic conductivity value observed for setaria grass was highest and the lowest value was recorded by guinea grass. Infiltration rate showed no significant difference among treatments. Soil temperature values were brought down by fodder grass cultivation during daytime, insulated the soil when it was cooled. There was no significant effect on the chemical properties of the soil namely, soil reaction , available nitrogen, available potassium, exchangeable calcium and exchangeable magnesium. Soil phosphorous level shown by the setaria grass was high, which was positively correlated with the soil temperature. Inter-cultivation with fodder grass in coconut garden, is not deteriorating the physical properties, but it can improve the hydraulic characteristics and thermal properties thereby leading to an increase in the coconut yield.