The short term effect of tillage on soil physicochemical properties in Bayelsa State, Nigeria

The objective of the research was to determine the effect of different crude tillage implements on some soil physicochemical properties in Niger Delta University Teaching and Research Farms. The land was divided into plots measuring 5 x 5m with three replicates per treatment. Five tillage treatments were considered (no-till, Hoeing, Digging, Hoeing + Digging once, and Hoeing + Digging twice) at 0-15cm and 15-30cm depth. At both depths, three samples were collected per plot and bulked to form one representative sample. A total number of thirty (30) samples were collected from the field. The research was laid out in the Randomized Complete Block Design. The result showed that the different crude tillage methods had no significant effect on the soil's chemical properties but had an effect on the physical. Mean pH ranged from 4.42 – 4.49 (strongly acidic), Electrical conductivity ranged from 65.67 – 82 ds/m (indicating no saline stress or detriment to crops), organic carbon and organic matter were moderate with a range of 18.52 – 21/55g/kg and 37.03 – 43.10 g/kg, Total Nitrogen was at its moderate range of 7.88 – 12.17 g/kg. Exchangeable acidity was low with a range of 1.52 – 1.71 cmol/kg. The soils were mainly coarse textured with the sandy fraction ranging from 635 – 795g/kg, silt (79.4 – 134.4g/kg), and clay (125.6 – 230.6 g/kg); the mean soil texture was mainly loamy sand with the No-Till zone been sandy loam. The crude tillage methods had significant impact on the soil bulk density and porosity; the highest bulk density was recorded in the No-till zone (1.18g/cm3) which decreased steadily with an increase in tillage intensity, with the Hoe+Digging (twice) recording the lowest value of 0.94g/cm3. Similarly, the highest porosity value was found in the tillage method with the lowest bulk density value (0.94g/cm3: 64.7%), while the lowest was found in the tillage method with the highest bulk density value (1.18g/cm3: 55.7%). pH had positive correlation (P<0.05) with electrical conductivity (r=0.62), organic carbon (r=0.94), organic matter (0.905, and negative correlation with exchangeable acidity (-0.522). Organic carbon had strong positive correlation with organic matter (r=0.99), effective cation exchange capacity (r=0.697), clay (r=0.502), and total nitrogen (r=0.607). Silt (r=0.737) and clay (r=0.705) showed positive relationship with bulk density; while bulk density (r= -0.995) showed strong negative correlation with porosity. It is therefore recommended that crude tillage methods be used for sustainable and conservative agriculture.