Effects of Different Rates of Nitrogen and Phosphorus Fertilizers on Growth and Yield of Potato (Solanum tuberosum) under Mechanized and Traditional Cultivation

Abstract

In the present study, half of the land was cultivated mechanically by tractor using a two-bladed mould board plough and nine tine harrow. The other half was cultivated by a local farmer who used a bullock and wooden plough. A single seed variety (Marabel) was sown across the entire trial site. Four separate identical fertilizer treatments were used across both the mechanized and traditionally cultivated sites. Phosphorous was applied in the form of diammonium phosphate. Nitrogen was applied in the form of Urea. FAO’s recommended rates for phosphorus (220kg/ha) and nitrogen (330kg/ha) were applied. In addition, additional rates below and above the FAO’s recommendations were also applied, with phosphorous being applied at 0 kg/ha, 110 kg/ha (50% of recommendation) and 440 kg/ha (200% of recommendation). Nitrogen was applied at 0 kg/ha, 165 kg/ha (50% of recommendation) and 660 kg/ha (200% of recommendation). Results on average revealed that across all four fertilizer rates, mechanized cultivation produced 60% higher crop yields (average 32.83mt/ha) compared with traditional cultivation (average 20.5 mt/ha) which resulted in an average of 12.33mt/ha higher yield for mechanized cultivation over traditional cultivation. This yield difference was highly statistically significant (P =0.99(. Additionally, the average gross margin per hectare was 74% higher across the mechanized plots (US$6,552/ha or 373,464AFN/ha) compared with the traditional plots (US$3,772/ha or 215,004 AFN/ha). These figures confirm that use of mechanized cultivation and the application of phosphorus at 440 kg/ha and nitrogen at 660 kg/ha will increase the potato yield and produce a higher cash value and a higher gross margin per hectare.