Effects of methods of fertilizer placement on fine beans (Phaselous vulgaris L.)growth and nutrient distribution in the soil

Abstract

This study was carried out at Natural Resources Development College-Zambia Export Grower's Association (NZTT), to determine the effects of three methods of fertilizer placement on fine beans growth and nutrient distribution during the 2001/2002 growing season. The three treatments that were evaluated and replicated four tunes in a randomized complete block design were band placement of fertilizer 7 cm from the seed row, broadcasting of fertilizer between the seed rows and placement of fertilizer 5 cm below the seed row. The fertilizer WVC (Wheat, Vegetables and Cotton) was applied at a rate of 175 kg/ha to provide 14 kg/ha N, 18 kg/ha P and 23 kg/ha K. The plant parameters observed were the leaf area per plant, plant height and root depth.Fine beans grown on plots where fertilizer was placed within seed row generally had higher mean values of leaf area, plant height and root depth than the other two treatments, although in most cases there were not always statistically significantly different from the plants grown on plots where the other two fertilizer application methods were used.To determine the nutrient distribution, soil samples were taken from 0-15 cm, 15-30 cm and 30-45 cm depths before planting and in the third, fifth, eighth and tenth week after planting. The electrical conductivity and the contents of phosphorus, nitrate nitrogen and ammonium nitrogen were determined in the soil samples were measured. No specific pattern was observed in the distribution of phosphorus and ammonium nitrogen. The concentration of nitrate nitrogen and the reading of the electrical conductivity, were higher in the fertilizer next to the seed row than, the fertilizer broadcast and the fertilizer within seed row. In all the treatments, the highest readings of the nutrients and the electrical conductivity were in the top 0-15 cm depth, while the lowest values were mostly observed in the 30-45 cm soil depth in most cases. There were no significant differences in the distribution of phosphorus. However, there were statistically significant differences in the distribution of nitrate nitrogen in the fifth week within both the 0-15 cm and the 30-45 cm soil depth. With ammonium nitrogen, there were statistically significant differences in the tenth week within the 30-45 cm depth. Statistically, there were significant differences in the case of the electrical conductivity in the eighth week within the 0-15 cm soil depth and in the tenth week within the 15-30 cm as well as within the 30-45 cm.