Exploring teff yield variability related with farm management and soil property in contrasting agro-ecologies in Ethiopia

Abstract

CONTEXTTeff is an important food-security crop for millions of people in Ethiopia. The demand for teff products is also increasing globally due to its health benefits as a gluten-free grain. However, teff productivity is low compared with other cereals. Crop yields vary widely among farms in rainfed production system. Identifying the key crop management practices and soil properties responsible for these variations will help to raise crop productivity through informed decision making by farmers, experts, researchers, and policy makers. OBJECTIVESThe objectives of this study were to assess the characteristics of the Ethiopian teff-cropping system, quantify the variability of grain yields among farms, and identify the impacts of different crop management practices and soil fertility parameters on yield variability. METHODSThe study examined 82 teff farms at three sites representing different teff-growing agro-ecologies in Ethiopia. Practices used to manage crops and soil on each farm were assessed. Composite topsoil samples were collected from farms at each site and analyzed for selected physical and chemical parameters. Grain and straw yields were quantified when crops were matured. Descriptive statistics, and factor analysis followed by multiple regression analysis was performed to identify the factors that caused the variability of yields among farms. RESULTS AND CONCLUSIONSTeff yields were highly variable within and across different agro-ecologies. The crop management factors that greatly affected yields were N and P application rates and days to harvesting. The most important soil characteristics were total nitrogen, texture and micronutrients. Poor teff yields were attributable to failure to implement improved agronomic practices, poor soil fertility, and inefficient production systems. Teff production system is a low-yielding, less-profitable, and resource-intensive enterprise. The observed variations in yields among farms indicated that there is a big opportunity to improve teff productivity. The high frequency of tillage, monocropping, and complete removal of crop residues were major causes of the low soil fertility. SIGNIFICANCEUnderstanding teff yield variability among farms helps to design appropriate yield improvement strategies. The use of low-cost crop-intensification options such as planting of improved cultivars using improved sowing methods, reduced tillage, incorporation of crop residues and legume-based crop rotation could sustainably improve productivity and restore soil fertility with minimal increases of costs in rainfed teff production system.