Lucerne (Medicago sativa) or grass-clover as cut-and-carry fertilizers in organic agriculture

On-farm nitrogen fixation is a driving force in organic agriculture. The efficiency with which this nitrogen is used can be increased by using lucerne (Medicago sativa) or grass-clover directly as sources of fertilizer on arable land: cut-and-carry fertilizers. In two arable crops, the use of lucerne and grass-clover as fertilizers was compared with the use of poultry manure and slurry. The nitrogen-use efficiency at crop level was comparable or better for the cut-andcarry fertilizers as compared to the animal manures. The relative P and K content of these fertilizers came closer to the crop demand than that of the poultry manure. Crop yields were comparable or better when using lucerne or grass-clover as fertilizer. It is concluded that cutand-carry fertilizers are a serious alternative for manure as part of an overall farm soil fertility strategy

Nutrient recycling from bio-digestion waste as green fertilizers

In the transition from a fossil to a bio-based economy, it has become an important challenge to maximally recuperate valuable nutrients coming from waste streams. Nutrient resources are rapidly depleting, significant amounts of fossil energy are used for the production of chemical fertilizers, whereas costs for energy and fertilizers are increasing. In the meantime, biogas production through anaerobic digestion produces nutrient-rich digestates. In high-nutrient regions, these products cannot or only sparingly be returned to agricultural land in its crude unprocessed form. The consequent processing of this digestate requires a variety of technologies producing a lot of different derivatives, which could potentially be re-used as green fertilizers in agriculture. As such, a sustainable alternative for fossil-based mineral fertilizers could be provided. The aim of this study is to characterize the physicochemical properties of digestates and derivatives, in order to identify the fertilizer value and potential bottlenecks for agricultural re-use of these products, in line with European legislative constraints. In addition, the economic and ecological benefits of substituting conventional fertilizers by digestates and derivatives are quantified and evaluated. Waste water from acidic air scrubbers for ammonia removal shows potential as N-S-fertilizer, whereas concentrates resulting from membrane filtrated liquid fraction of digestate show promise as N-K-fertilizer. Substituting artificial fertilizers by air scrubber water or membrane filtration concentrates theoretically always results in significant economic and ecological benefits for the agriculturist. Field research is now on-going in order to evaluate the impact on soil and crop production by application of these new green fertilizers

Conceptualising Graduation from Agricultural Input Subsidies in Malawi

The government of Malawi has been implementing agricultural input subsidies since 2005/06 as an intervention aimed at improving food security among resource poor smallholder farmers. Although the issue of graduation is not articulated in the design of the programme, this study investigates the determinants of changes in the demand for commercial fertilizers in the presence of the subsidy programme. The increase in purchase of commercial fertilizers by subsidized households may indicate prospects of graduation from the subsidy programme in future. Using panel data between the 2004/05 and 2008/09 seasons, we find that 6 percent of households that did not purchase commercial fertilizer in 2004/05 could afford to purchase fertilizers commercially in subsidy years. Relative to those that never purchase fertilizers, these households tend to have higher per capita expenditure and higher values of durable assets. The econometric results show that initial conditions matter, with initial household size, per capita expenditure, agricultural output, and existence of business enterprise all playing a positive role in the changes in demand for commercial fertilizer. We also find that commercial fertilizers decreases with initial commercial fertilizers, land holdings and existence of ADMARC. The results suggest that the poor may have low prospects of graduation and less involvement of ADMARC and greater participation of the private sector can help in improving the ‘potential graduation conditions’

Initial Conditions and Changes in Commercial Fertilizers under the Farm Input Subsidy Programme in Malawi: Implications for Graduation

The government of Malawi has been implementing agricultural input subsidies since 2005/06 as an intervention aimed at improving food security among resource poor smallholder farmers. Although the issue of graduation is not articulated in the design of the programme, this study investigates the determinants of changes in the demand for commercial fertilizers in the presence of the subsidy programme. The increase in purchase of commercial fertilizers by subsidized households may indicate prospects of graduation from the subsidy programme in future. Using panel data between the 2004/05 and 2008/09 seasons, we find that 6 percent of households that did not purchase ommercial fertilizer in 2004/05 could afford to purchase fertilizers commercially in subsidy years. Relative to those that never purchase fertilizers, these households tend to have higher per capita expenditure and higher values of durable assets. The econometric results show that initial conditions matter, with initial household size, per capita expenditure, agricultural output, and existence of business enterprise all playing a positive role in the changes in demand for commercial fertilizer. We also find that commercial fertilizers decreases with initial commercial fertilizers, land holdings and existence of ADMARC. The results suggest that the poor may have low prospects of graduation and less involvement of ADMARC and greater participation of the private sector can help in improving the ‘potential graduation conditions’

Fertilizers for Ohio Farms

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Effects of organic fertilisers and compost extracts on organic tomato production

The effects of various fertilizers and different compost extracts on crop health and tomato yield were studied in the field in 2004–2005 in two locations in Iran. Treatments included different fertilizers (cattle, sheep and chicken manures, green waste and household composts and chemical fertilizers) and five aqueous extracts (from cattle manure, chicken manure, green-waste and house-hold composts and water as control). The effect of fertilizer type on tomato yield was significant in both locations (P < 0.05). Organic fertilizer use did not obtain higher yields compared to using chemical fertiliser. Generally, chicken manure and green-waste compost led to the highest and lowest tomato yield among different organic fertilizers, respectively. The effect of aqueous extracts was not significant on either crop health or tomato yield with these results were being very limited and inconsistent. Improved efficacy of acceptable alternatives to agrochemicals, especially in organic farming, is required

The mineralization of commercial organic fertilizers at 8°C temperature

In organic production only organic fertilizers and soil conditioners can be used to supply the soil with nitrogen. The mineralization of these products is slow and so there can be problems with the supply of nitrogen, when the demand of the plants is high. The supply of nitrogen from organic products depends on the speed of their mineralization which is primarily influenced by the composition and formulation of their raw material. In apple production in the Alps-region especially during spring problems with nitrogen supply are common. In that period, the weather conditions are sometimes bad, the temperature in the soil is low and mineralization starts slowly - apple trees demand more nitrogen than the soil can deliver. To compensate the demand of the apple tree organic growers can not use mineral fertilizers but only organic fertilizers and soil conditioners whose mineralization rate is often unknown. There is a strong need in organic fruit production to receive more information about the behaviour of fertilizers in the soil especially concerning their N-release under different conditions. To acquire that information, incubation experiments under controlled conditions (temperature, type of soil, humidity of the soil) were carried out in the laboratory to determine the mineralization-rate of different organic fertilizers and soil conditioners which are available in our region

Gender and Intra-Household Use of Fertilizers in the Malawi Farm Input Subsidy Programme

The Farm Input Subsidy Programme targets households for subsidized farm inputs, and usually it is the head of the household who receives the coupons. Since households tend to have multiple plots which are controlled by different members of the household, there may be intra-household issues that arise in the use of farm inputs available to the household. We find that while male-headed households are more likely to receive coupons than female-headed households, there seems to be less bias in intra-household use of subsidized fertilizers (or fertilizers in households receiving subsidy) between plots controlled by female and male members. This is despite the fact that, more generally, household incomes from various sources tend to be controlled and allocated by men. It also contrasts with evidence that plots controlled by female members were less likely to be applied with fertilizers when we consider all fertilizers in subsidized and unsubsidized households