Recent human population increase has been enabled by a massive expansion of global agricultural production. A key component of this "Green Revolution" has been application of inorganic fertilizers to produce and maintain high crop yields. However, the long-term sustainability of these practices is unclear given the eutrophying effects of fertilizer runoff as well as the reliance of fertilizer p...

In earlier work, we compared the amount of newly fixed nitrogen (N, as synthetic fertilizer and biologically fixed N) entering agricultural systems globally to the total emission of nitrous oxide (N(2)O). We obtained an N(2)O emission factor (EF) of 3-5%, and applied it to biofuel production. For 'first-generation' biofuels, e.g. biodiesel from rapeseed and bioethanol from corn (maize), that re...

In 1990 and 1991, populations of the cabbage aphid, Brevicoryne brassicae, and the green peach aphid, Myzus persicae, were monitored on broccoli interplanted with three leguminous cover crops (the living mulches) and compared with broccoli without cover crop (clean cultivation). The cover crops used were white clover ( Trifolium repens L.), strawberry clover (Trifolium fragiferum L.) and a mixt...

AIMS The recent increases in food prices caused by the corresponding increases in fertilizer costs have highlighted the demand for reducing the overuse of fertilizers in industrial agriculture. There has been increasing interest in developing plant root-targeted delivery (RTD) of fertilizers in order to address the problem of inefficient fertilizer use. The aim of this study is to develop a low...

Nutrient management is central in water footprint analyses as it exerts strong control over crop yield and potentially contributes to pollution of freshwater, the so-called grey water footprint. In the frame of grey water footprint accounting, two methods are suggested, the constant leaching fraction approach (10% of applied fertilizer N) and the N surplus approach. We compared both approaches ...

Currently the world is moving towards organic production of crops for the discovered and envisaged advantages. Despite this, farmers are faced with the challenges of the bulkiness of organic fertilizer to be used and further gains that could be accrued from it even if sacrifice of using it is made. To be quite sure of the appropriate fertilizer type to be used in improving quality as well as th...

Fertilizer application is a common anthropogenic alteration to terrestrial systems. Increased nutrient input can impact soil microbial diversity or function directly through altered soil environments, or indirectly through plant-microbe feedbacks, with potentially important effects on ecologically-important plant-associated mutualists. We investigated the impacts of plant fertilizer, containing...

1 Why don’t farmers use fertilizers: 2 Evidence from Field Experiments in Western Kenya 3 (PRELIMINARY AND INCOMPLETE) 4 April 29, 2006 5 6 Esther Duflo, Michael Kremer and Jonathan Robinson 7 8 9 Abstract 10 11 This paper reports on randomized field experiments set up to investigate 12 various reasons for the low usage of fertilizer in Western Kenya. 13 Demonstration plots set up on farmer’s f...

Nitrous oxide (N2O) is a potent greenhouse gas (GHG) that also depletes stratospheric ozone. Nitrogen (N) fertilizer rate is the best single predictor of N2O emissions from agricultural soils, which are responsible for ∼ 50% of the total global anthropogenic flux, but it is a relatively imprecise estimator. Accumulating evidence suggests that the emission response to increasing N input is expon...

A Bulgarian project at Maritsa East power station demonstrated the proper transformation of air pollutants (SOx and NOx) into nitrogen fertilizer. Although this technology has not been put into practice in Bulgaria, it seems feasible on an industrial scale and so it may help to ease Portugal’s reliance on imports of nitrogen fertilizer and thereby contain the outfl ow of Portuguese funds. The d...