Variation in Soil Properties under Long-Term Irrigated and Non-Irrigated Cropping and Other Land-Use Systems in Dura Catchment, Northern Ethiopia

Abstract

There are limited reports about the impacts of long-term irrigated and non-irrigated cropping and land-use systems (CLUS) on soil properties and nutrient stocks under smallholder farmers’ conditions in developing countries. The objective of this research was to examine variation in soil properties and OC and TN stocks across the different CLUS in Dura sub-catchment, northern Ethiopia. Surveys and discussions on field history were used to identify nine CLUS, namely, tef (Eragrostis tef (Zucc) Trot)) mono-cropping (TM), maize (Zea mays L.) mono-cropping (MM), cauliflower (Brassica oleracea var. botrytis)-maize intercropping (IC1), red beet (Beta Vulgaris)-maize intercropping (IC2), cauliflower-tef-maize rotation (R1), onion (Allium cepa L.)-maize-onion rotation (R2), treated gully (TG), untreated gully (UTG), and natural forest system (NF). A total of 27 composite soil samples were collected randomly from the CLUS for laboratory analysis. Data were subjected to one-way analysis of variance and PCA. The lowest and highest bulk density was determined from NF (1.19 Mg m^-3) and UTG (1.77 Mg m^-3), respectively. Soil pH, EC and CEC varied significantly among the CLUS. The highest CEC (50.3 cmol_c kg^-1) was under TG followed by NF. The highest soil OC stock (113.6 Mg C ha^-1) and TN stock (12.2 Mg C ha^-1) were found from NF. The PCA chosen soil properties explained 87% of the soil quality variability among the CLUS. Such soil properties and nutrient stocks variability among the CLUS suggested that introduction of suitable management practices are crucial for sustaining the soil system of the other CLUS.