RESEARCH FELLOW II, INSTITUTE FOR AGRICULTURAL RESEARCH/AHMADU BELLO UNIVERSITY, ZARIA, NIGERIA
Evaluating two maize varieties under ISFM with the inclusion of secondary macro and trace elements
In Nigeria,one fertilizer recommendation applies to the whole country or a wide region. However, farmers operate under varying conditions within the agricultural landscapes of Nigeria and we often observe a very strong variability in yield, locally or within districts. This variability is explained largely by soil fertility gradients, either management induced or because of varying inherent soil fertility. Recognizing the wide variability in soils and management, it becomes necessary to fine tune current recommendations in order to target investments such that chance of success is improved while the risks are reduced. In order to increase the use efficiency of applied nutrients and the cost effectiveness of resource input, there is need to target interventions whether related to soil amendments to improve the condition of the soil or to fertilizer application to address nutrient requirements. In Nigeria and other tropical countries, research interest recently shifted to utilization of organic wastes as nutrient source in crop production. This is due to high cost and scarcity of mineral fertilizers. As such, it is necessary to integrate chemical fertlizers into organic sources to reduce the quantity and enhance nutrient uptake (Ayeni and Adetunji, 2010). Despite various fertilizer recommendations, maize yields in tropical forest and savannah zones are very low. These low yields could be attributed in part to the exclusion of some secondary and all micro nutrients in fertilizer recommendations for maize, a condition which often leads to nutrient imbalance. The inclusion of some secondary and micro nutrients in fertilizer recommendation for successful maize cultivation in this zone has been suggested (Agboola and Cory, 1976; Kayode and Agboola, 1981) but no one has proposed a balanced nutrient program for this purpose. It is in this light that this work is geared towards -Determining maize’s response to integrated nutrient application in terms of growth, yield and nutrient uptake from soil and foliar spectral under varying soil fertility conditions.
Abstract: Throughout much of Sub-Saharan Africa (SSA), maize production is characterized by low productivity due to the scarce availability and use of external inputs and recurrent droughts exacerbated by climate variability. Within the integrated soil fertility management (ISFM) framework, there is thus a need for optimizing the application of fertilizers and manure to better use the limited nutrient resources and increase crop yield and farmer income. An on-station experiment was conducted in Northern Benin over a 4-year period to evaluate the effect of hill placement of mineral fertilizer and manure on maize yields and soil chemical properties. The treatments consisted in the combination of three rates of manure (0 (NM), 3 (3M) and 6 (6M) Mg ha−1) and three levels of fertilizer (0% (NF), 50% (50F) and 100% (100F) of the rate recommended by extension (76 kg N + 13.1 kg P + 24.9 K ha−1)). On average across the fertilizer rates, hill-placement of manure significantly improved soil organic carbon content, available P and exchangeable K after 4 years by up to 124, 166 and 77%, respectively, compared to the initial values. As a result of the nutrient inputs and improved soil properties, yields increased steadily over time for all manure and fertilizer combinations. Value-cost ratios and benefit–cost ratios were >2 and generally as good or even better for treatments involving 50F compared to NF or 100F. Although applying half the recommended rate of fertilizer without manure as currently done by many farmers appears to make economic sense, this practice is unlikely to be sustainable in the long term. Substituting 50F for 3M or complementing 50F with 3M are two possible strategies that are compatible with the precepts of ISFM and provide returns on investment at least as good as the current practice. However, this will require greater manure production, made possible in part by the increased stover yields, and access to means of transportation to deliver the manure to the fields.
Pub.: 11 Aug '17, Pinned: 22 Mar '18