Characterization of soils developed on nupe sandstone and their suitability for sugarcane (Saccharum officinarum L.) in Southern Guinea Savanna, Nigeria

Abstract

Soils developed from Cretaceous Nupe Sandstones parent materials were surveyed to characterise and assess their suitability for sugarcane production on a 35.7 ha land area. The study area was surveyed at detailed scale of 1:4,000 using rigid grid method. Three soil mapping units were delineated namely: BKG I (10.40 ha; 29.70 %), BKG II (20.90 ha; 59.50 %) and BKG III (3.80 ha; 10.80 %). Morphologically, the soils were very deep (177 - 220 cm) on level to nearly level topography dominated by loamy sand over sandy loam and sandy clay loam textures. Drainage varied between very poorly drained (BKG I), moderately drained (BKG III) and well drained (BKG II). Physical properties indicate sand fraction dominated the particle size, while available water capacity was low and ranged between 3.30 and 7.51 cm/120 cm soil depth. Chemical properties showed that, soil reaction (pH) varied between 5.65 and 6.80, and rated moderately acid to neutral. Electrical conductivity, ESP and SAR were low, and therefore considered as non-saline and non-sodic. Cation exchange capacity was low to medium and was attributed to Nupe sandstone parent material. However base saturation varied between medium and high (59.91 - 84.88 %). Organic carbon and total nitrogen were generally low, while available micronutrient Fe was generally high across the soil units. The soils were classified as Typic endoaqualfs, Arenic Hapludalfs and Arenic endoaqualfs for soils of units BKG I, BKG II and BKG III respectively, and correlated with Gleyic Luvisols (BKG I and BKG III) and Haplic Luvisols in WRB Soil Resource 2014. Actual suitability based on parametric evaluation for sugarcane showed that the soils were classified as moderately suitable (S2csf) for BKG II and marginally suitable (S3cswf) for BKG I and BKG III. Sustainable management practices like incorporation of crop residue, application of organic and inorganic fertilizers was suggested to reduce the limitations and upgrade the land suitability for sugarcane production in the study area.