Savanna Journal of Basic and Applied Sciences 3(1):1-9
Soil-Plant Interactions in Ipomoea asarifolia and Cynodon dactylon in Sudan Savanna Ecological Zone, Northwestern Nigeria
Anka S.A., 1Aliero B.L., Aliero A.A. and Noma S.S.

The interaction effects of two cover crops, Ipomoea asarifolia L. (Ders.) Roem & Schult and Cynodon dactylon (L.) Pers. on soil properties was investigated. Soil samples (0-20 cm depth) taken before and after cover cropping were analyzed using appropriate methods. In the results, silt proportion shows marked improvement under cover cropping (8.37 to 20.52%) than in the control (7.90 to 9.25%). Increase in clay (2.15 to 2.50%) and decrease in sand (88.86 to 87.85%) were observed in soils under the cover cropping. The clay content under I. asarifolia (2.67 to 2.83%) did not vary significantly (P < 0.05) whereas that under C. dactylon (1.72 to 3.08%) had significant variation (P > 0.05). Bulk density (1.82 to 1.95g/cm3 and 1.69 to 1.85g/cm3 and moisture (1.25 to 1.33% and 1.83 to 2.25%) under I. asarifolia and C. dactylon respectively were lower than particle density (1.89 to 2.24 and 2.22 to 2.25 g/cm3 under I. asarifolia and C. dactylon respectively. Soil pH value ranges from moderately acidic (5.90) under C. dactylon to slightly acidic (6.47) under I. asarifolia. Organic carbon (0.24 to 0.29%) and organic matter (0.47 to 0.55%) were higher under C. dactylon. Nitrogen was higher (0.05 gkg-1) under I. asarifolia and lower (0.03 to 0.04 gkg-1) under C. dactylon. Available P was higher (0.88 to 0.93 gkg-1) under dense cover and lower (0.56 to 0.76 mg/kg) under sparse cover of the two species. Exchangeable bases were generally higher under cover cropping than in the control: Ca2+ (0.35 to 0.62 cmolkg1), Mg2+ (0.27 to 0.71 cmolkg-1) and K+ (0.90 to 1.09 cmolkg-1) were higher under I. asarifolia whereas Na+ (0.82 to 0.85 cmolkg1) was higher under C. dactylon. The mixed cover cropping of the two species, having higher CEC values of 3.45 and 3.55 cmolkg-1, is critical to sustenance of soil fertility against weather adversities and human activities. Cover cropping is best between farming seasons to avoid competition with cultivated crops.