Growth and Yield Components of Pisum Sativum L. (Pea) in Response to Rhizobium Bio-fertilizer Supplemented with Carrier Materials (Earthworm Castings and Poultry Litter)

Abstract

The indiscriminate use of chemical fertilizers to increase the soil nutrients and the use of pesticides is one major problem facing crop farming. Hence, the use of bio-fertilizers can be a very good complimentary to the chemical fertilizers as they not only promote crop growth and yield but also maintain soil health for sustainable agriculture. The growth and yield components of pea (Pisum sativum L.) in response to Rhizobium bio-fertilizer supplemented with earth worm casts and poultry litter was evaluated in this study. Soya bean (Glycine max L.) was cultivated to obtain the root nodules needed for the isolation of Rhizobium species. The nodules were sterilized, crushed, serial dilutions prepared, inoculated on Yeast Extract Mannitol Agar (YEMA) medium and incubated at 28+°C. Pure culture of Rhizobium was isolated, mass produced and then mixed with autoclaved earthworm casts and poultry litter and separately for application unto the experimental crops. The Rhizobium broth and the supplements were mixed in the ratio of 2 litres to 100 kg. Analyses of experimental soil, poultry litter and earthworm casts were carried out to determine their physico-chemical properties. Four treatments (three fertilizer types and control were replicated four times and arranged in a Randomized Complete Block Design (RCBD). These treatments are: Chemical fertilizer (CHF), Rhizobium bio-fertilizer plus poultry litters (BP), Rhizobium bio-fertilizer plus earthworm cast (BEC) and a negative control (without fertilizer). Ten kilogram of the fertilizer types each was applied to the ridges grouped into 4 plots (A, B, C and D) according to the fertilizer types and the control. Plant’s growth and yield parameters of pea grown on soil amended with the bio-fertilizers supplemented with earthworm casts and poultry litter, inorganic fertilizers and the control were measured and compared. The results of the analysis of physico-chemical properties of the soil, earthworm casts and poultry litters reveal that experimental soil had a mean pH value of 6.23, while those of the earthworm cast and the poultry litter were 5.78 and 8.63 respectively. Poultry litter had the highest organic matter content of 58.25% followed by earthworm cast which had 6.00%, while the experimental soil had the least (1.41%). The percentage of nitrogen was highest in poultry droppings (3.20%), followed by earthworm casts (0.19%) and the least value (0.0 %) was obtained from the soil. The present findings showed an improvement in the growth and yield parameters of pea grown on soil amended with Rhizobium bio fertilizers and chemical fertilizer over the control. Although, the highest improvement recorded in the growth and yield of pea was from bio-fertilizers supplemented with poultry droppings and earthworm casts, there was no significant difference at (p>0.05) in the growth and yield parameters of pea in relation to various fertilizer treatments. Hence, the total yield of pea seed was found to be uniform 2.4 t/ha each for all the treatments except in the control which had the lowest yield (0.7 t/ha). The outcome of this study is important in that farmers can fall back on Rhizobium biofertilizer for the cultivation of pea, since the inorganic fertilizers are very expensive such that most poor farmers cannot afford them.