Abstract
In a pot experiment, the effects of nitrogen source and soil texture were stud-ied on the growth of rnazenta fodder under saline-sodic soil condition. An increase of 38 and 36% in fresh matter was observed through the application of ammonium sulphate over urea in sandy loam and clay loam soils, respectively. Both the nitrogen sources showed a significant increase in the fresh and dry matter yields. With the application of nitrogen fertilizers, significantly higher nitrogen but lower phospho-rus, potassium, chloride and sodium concentrations in plants were observed com-pared to the control plants. In clay loam, 7% higher fodder yield was obtained than that in sandy loam soil.
INTRODUCTION
*Mazente is a new high yielding fodder crop, evolved as a hybrid by crossing maize (Zea mays L.) as female and "teopak" (Zea maricana ) as male parents. Under different soil and climatic conditions, soil salinity and sodicity, water stress, specific ion stress or toxicity and nutrient imbalance might be the possible causes for reduction in growth (Wyn Jones, 1981).
Under saline and sodic soil conditions, the N requirement for optimum yields might increase because adverse soil conditions modify the nature and extent of N transfor-mations (Bhardwaj and Abrol, 1976). An adequate supply of nitrogen is associated with vigorous vegetative growth and a dark green colour (Tisdale et al., 1985). More-over, it produces succulence, a quality, par-ticularly required for fodder crops.
Due to more acidifying effect as well as lower nitrogen losses (20%) from ammo-nium sulphate than urea, it gave significantly higher yields than the other nitrogen sources
(Aggarwal et at, 1986). Nitrogen efficiency showed a negative correlation with the sand percentage of soil (Vaughan et al., 1990) as nitrogen losses might increase from coarse textured soils. The present investigation was, therefore, undertaken to assess the perfor-mance of "mazenta" fodder and relative effi-ciency of two nitrogen sources in different textured saline-sodic soils.
MATERIALS AND METHODS
The pot-culture study was conducted in the wire-house, Department of Soil Science, University of Agriculture, Faisalabad during 1989-90. Two soils, sandy loam and clay loam, were collected from Pindi Bhattian and Sadhoke areas, respectively (Table 1). Ten kilogram air-dried, sieved and thor-oughly mixed soil was added in each pot. In both the soils, nitrogen was applied at rates of 0, 150 and 200 kg ha-1 in the form of urea as well as ammonium sulphate. Half of the nitrogen was applied at sowing and remain-ing half twenty days after germination. A basal dose of P205 @ 100 kg ha-1 was ap-plied as single superphosphate (SSP).
