Mathematical Model Equation for Tolerance of Okra Plant Yield to Soil Densification

International Journal of Research and Innovation in Applied Science (IJRIAS) | Volume V, Issue III, January 2020 | ISSN 2454–6186

 Mathematical Model Equation for Tolerance of Okra Plant Yield to Soil Densification

 Adeye Silas O. Nkakini1 and Davies, R.M.2
1Department of Agricultural and Environmental Engineering, Rivers State University, Port Harcourt Rivers State, Nigeria
2Department of Agricultural and Environmental Engineering, Niger Delta State University, Bayelsa State, Nigeria

Abstract- Soil plays vital role in plants performance. A densified agricultural soil has lost its nutrients availability to plants. Thus the study is on modelling the tolerance of Okra (Abelmoschus esculentus L.) to soil densification under varying degrees of tractor passes on the sandy loam soil. The research was conducted at the Rivers Institute of Agricultural Research and Training, South-South, Nigeria. The plot of area 46m by 36m was cleared of grasses, debris and stumps. The soil samples were randomly collected for soil tests before and after tillage operations such as ploughing and harrowing + harrowing which were carried out respectively. The land space was marked out into randomized complete block design of four replicates compacted at i = 0, 5, 10, 15 and 20 passes per replicate of which there were twenty subplots altogether with a SWARAJ 978 FE Tractor Model used for the compaction routines. A duly certified Okra seeds bought from the Government of the Rivers State Ministry of Agriculture, Crop Department with minimum percentage germination and purity of 85% and 99% were sown by placing 3 seeds per hole at a considerable depth of about 0.03m beneath soil surface, with inter-row and intra-row spacing of 0.6m by 0.6m and a 4m by 4m alley dimension which was marked out to separate each subplot from the other. The seedlings were later thinned to two Okra plants per stand at two weeks after emergence. The data obtained were employed in model development. A mathematical model equation (γ_p )_i= φ((ω ̇_p )_(i ) √((ρ_d )_i (CI)_i ))/D_c + C_1, was developed based on Buckingham pi theorem using dimensional analysis to predict tolerance of Okra yield under soil compaction. A Least Square estimation to depict φ, the constant of proportionality of the modelled equation was estimated at 4 x 106 and C1= 3 x 10-5. The model obtained was verified and validated using Analysis of variance (ANOVA) and t-test to determine if there were significant differences between the experimented and predicted values of Okra yield measurements. It was clear evident after the tested modelled equation that there was an approximately closed agreement between the experimented and modelled values of Okra yield in tolerance to soil compaction at varying tractor passes in different subplots. Hence, it was suggested that the model be used for Okra yield prediction in a densified soil.
Keywords: Tillage operations, densified soil, tractor passes, tractor model, tolerance, okra yield

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