Combining hill-placed manure and mineral fertilizer enhances maize productivity and profitability in northern Benin

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

Hill-placement of manure and fertilizer for improving maize nutrient- and water-use efficiencies in the northern Benin

Optimizing the use of organic and mineral fertilizer in rain-fed maize production is crucial for sustainable food production in sub-Saharan Africa. This study investigates the effect of hill-placement of two nutrient sources (farmyard manure and synthetic fertilizer) on nutrient- and water-use efficiencies of maize crops i.e. recovery efficiency (NUEre), internal utilization efficiency (NUEie) and water use efficiency (WUE). A four-year trial was conducted in the tropical sub-humid zone of the northern Benin with a factorial combination of farmyard manure at three levels (0, 3 and 6 t ha−1, hereafter NM, 3M and 6M, respectively) and three levels of fertilizer [0% (NF), 50% (50F) and 100% (100F) of the recommended rate (76 kg N + 13.1 kg P + 24.9 kg K ha−1) by the national center for agricultural research. The NUEre decreased with increasing rate of manure and/or fertilizer, but the decreasing rate was lower under combined manure and fertilizer application. However, the NUEie increased with the increasing manure and fertilizer amounts. The WUE was significantly higher in 3M and 6M treatments than in NM treatment, and higher in 50F and in 100F than in NF treatments. The combination of 3000 kg ha−1 farmyard manure with half recommended fertilizer rate (100 kg ha−1) could be suggested as an optimal nutrient management practice for maize production in the Northern Benin. Future studies should target the other agro-ecological zones in Benin, and also consider other widely cultivated crops in the study area for reducing yield gaps and promote food security

Efficient use of nutrients and water through hill-placed combination of manure and mineral fertilizer in smallhoder maize farming system in northern Benin

Maize, a major staple food in many farming systems in sub-Saharan Africa, 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 framework, there is thus a need for optimizing the use of fertilizers and manure for the efficient use of limited nutrient resources and rainfall, and to increase crop yield and farmer income

Crop Response to Leaf and Seed Applications of the Biostimulant ComCat® under Stress Conditions

Although clear evidence for benefits in crop production is partly missing, several natural compounds and microorganisms have been introduced to the market as biostimulants. They are supposed to enhance nutrient efficiency and availability in the rhizosphere, reduce abiotic stress, and improve crop quality parameters. Biostimulants often derive from natural compounds, such as microorganisms, algae, and plant extracts. In this study, the commercial plant extract-based biostimulant ComCat® was tested in two field experiments with maize in the communities of Banikoara and Matéri in Northern Benin and six pot experiments (four with maize and two with winter barley) at the University of Hohenheim in Germany. Maize was grown under nutrient deficiency, drought, and weed competition, and winter barley was stressed by the herbicide Luximo (cinmethylin). ComCat® was applied at half, full, and double the recommended field rate (50, 100, and 200 g ha−1) on the stressed and unstressed control plants as leaf or seed treatment. The experiments were conducted in randomized complete block designs with four replications. The above-ground biomass and yield data of one experiment in Benin were collected. The biostimulant did not promote maize and winter barley biomass production of the unstressed plants. When exposed to stress, ComCat® resulted only in one out of eight experiments in higher barley biomass compared to the stressed treatment without ComCat® application. There was a reduced phytotoxic effect of cinmethylin after seed treatment with ComCat®. Crop response to ComCat® was independent of the application rate. Basic and applied studies are needed to investigate the response of crops to biostimulants and their mechanisms of action in the plants before they should be used in practical farming