PAPER TITLE :TILLAGE EFFECTS ON SOME SOIL PHYSICAL PROPERTIES AND YIELD OF COWPEA (VIGNA UNGUICULATA) IN THE HUMID RAIN FOREST OF AKURE, NIGERIA

FUTA JOURNAL OF ENGINEERING AND ENGINEERING TECHNOLOGY | VOLUME 9 NUMBER 1 2015

Paper Details

  • Author(s) : Fasinmirin J. T. and Adesigbin A. J.
  • Abstract:

Tillage operations have a major influence on the penetration resistance and physical characteristics of soils, roots
growth, biomass and grain yield of tropical crops. Field experiment was conducted on sandy clay loam soil of Akure
in the south west of Nigeria to determine the influence of different tillage systems on soil bulk density, penetration
resistance, moisture content and growth characteristics of cowpea. There were three soil treatments plots A, B and C
each with 5 x 11.2 m2 dimension. The treatment applied on plot A was zero-tillage treatment (ZT) using paraquat
herbicide, plot B had Minimum tillage (MT) using light implement (cutlass and hoe) while the plot C was under
conventional tillage system (CT) using tractor mounted disc plough. The soil tillage treatments were replicated four
times in a randomized complete block design totalling 12 plots. Zero-tillage progressively increased soil bulk density
between 1.59 g cm-3 to 1.91 g cm-3 at the 0-30 cm soil depth. Highest moisture content of 15.98 % was obtained at the 0
– 10 cm soil layer in plots under zero tillage at the 5 weeks after planting (5WAP). During the 5th week after planting,
soil penetration resistance ranged from 710 kPa under zero tillage to 680 kPa under minimum tillage and 340 kPa
under disc ploughed plots (conventional tillage). Disc ploughed plots which produced the lowest soil penetration
resistance gave the best cowpea (Vigna unguiculata) yield, an indication of the need for soil pulverization to enhance
crop growth and yield. The results show that tillage treatments affect moisture retention, especially at 20 – 30 cm soil
layers and thus the ease of cowpea roots penetration resulting in improved cowpea growth and yield parameters. The
highest grain yield of cowpea with mean value of 0.64 (±0.03) t ha-1 was obtained in plots under convectional tillage
treatment. The mean grain yield of 0.52 (±0.03) t ha-1 was recorded in plots under minimum tillage while zero tillage
revealed a mean yield value of 0.41(±0.02) t ha-1. Finding from the research showed that the yield and yield
components of cowpea were raised in the plots under conventional tillage system compared with other tillage
systems.
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