Assessment of NPK, poultry manure and organo-yield biochar on productivity of cabbage (Brassica oleracea)

Abstract

The nature and characteristics of nutrient release of inorganic and organic fertilizers are different, and consequently, each type of fertilizer has its influence on crop growth and yield. A field experiment was conducted at NaCRRI, Namulonge to investigate the effect of different fertilizers on cabbage (Brassica oleracea) productivity. There were four treatments namely; NPK (17:17:17), organo-yield biochar, poultry manure, and control with three replications. The experiment was based on the hypothesis that the use of organo-yield biochar leads to higher yields compared to that of NPK and poultry manure in cabbage. Various growth parameters were assessed at 20, 40, and 60 days after transplanting (DAT) and yield parameters were assessed once at harvest. Results showed that generally fertilizer application increased the growth and yield of cabbage significantly compared to the control. At 20 and 40 DAT, the highest plant leaf number was observed in organo-yield and poultry manure respectively. NPK had the highest values of rosette diameter and plant height at both 40 and 60 DAT while the lowest values were observed in control. Stem height did not significantly vary amongst the treatments. Poultry manure had the highest leaf appearance rate from 20 to 40 DAT and the lowest observed in control. Control took the longest time to form heads. NPK showed a superior effect on the head traits and closely followed by organo-yield while the lowest observed in control. The marketable weight did not significantly vary amongst the treatments. The use of organo-yield biochar can be recommended to cabbage growers of Uganda. More research is needed to investigate the effect of organo-yield biochar for more than one growing season on different cabbage varieties and also the effect of combining organo-yield biochar with inorganic fertilizers on productivity of different vegetables.