Effect of Rhizobium Inoculation and Rock Phosphate Fertilizer on Soil Chemical Properties under Selected Green Grams Varieties


This study set out to ascertain the impact of Rhizobium and rock phosphate fertiliser application on the chemical characteristics of soil in green gramme types. The investigation was conducted over two seasons at the horticulture research farm of Chuka University (November 2019 – January 2020 and February – April 2020). A randomised full block design was used to set up a two by two by two factorial experiment (RCBD). Three variables were used to create a total of eight treatments that were duplicated three times: Rhizobium inoculation (0 and 100 g ha-1), rock phosphate (0 and 30 kg P ha-1), and variety (N26 and KS20). Soil pH, fixed-N, total nitrogen (TN), exchangeable cations (EC), accessible phosphorus (P), total organic carbon (TOC), and exchangeable potassium (K) were sampled and examined before and after green-grams were planted and harvested. The 15th edition of GENSTAT was used to analyse the data (P (leq) 0.05). The combined application of rock phosphate at 30 kg P ha-1 and Rhizobium inoculation at 100 kg ha-1 resulted in a significantly (P(leq)0.05) larger improvement in soil chemical characteristics than other treatments, according to results from both seasons. Although the soil pH (7.54), TN (0.58%), TOC (3.45%), P (68.20 ppm), EC (0.95 CmolKg-1), fixed-N (0.50%), and K values were considerably higher for treatment R1P1KS20 (1.75 CmolKg-1). The treatment R0P0N26, on the other hand, produced significantly (P(leq)0.05) lower results in the soil’s pH (5.23), TN (0.04%), TOC (1.86%), P (8.76 ppm), EC (0.21 CmolKg-1), and K. (0.58 CmolKg-1). Rhizobium inoculation in green-grams with rock phosphate is therefore a crucial method for enhancing legume nitrogen fixation. With the use of this technology, farmers may replace the nitrogen and phosphorus in their crops in a way that is both efficient and improves soil fertility management. Based on the results, Rhizobium 100g ha-1 and rock phosphate 30 kg P ha-1, as well as the variety KS20, should be included in a sustainable soil fertility management strategy in Tharaka Nithi County.

Author(s) Details:

F. K. Mbaka,
Department of Plant Sciences, Chuka University, P.O.Box 109-60400, Kenya.

H. O. Ndukhu,
Department of Plant Sciences, Chuka University, P.O.Box 109-60400, Kenya.

G. O. Oloo-Abucheli,
Department of Plant Sciences, Chuka University, P.O.Box 109-60400, Kenya.

Please see the link here: https://stm.bookpi.org/CTAS-V8/article/view/7253

Keywords: Agricultural productivity, nitrogen fixation, RCBD, Rhizobium inoculation, green-gram varieties, soil fertility.

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