Evaluation of the GreyWater Footprint Comparing the Indirect Effects of Different Agricultural Practices

Increasing global food demand and economic growth result in increasing competition over scarce freshwater resources, worsened by climate change and pollution. The agricultural sector has the largest share in the water footprint of humanity. While most studies focus on estimating water footprints (WFs) of crops through modeling, there are only few experimental field studies. The current work aims to understand the effect of supposedly better agricultural practices, particularly precision agriculture (variable rate application of fertilizers and pesticides) and conservation agriculture (minimum, strip, or no-tillage), on water deterioration and water pollution. We analyzed the results from an experimental field study in the northeast of Italy, in which four different crops are grown across three years of crops rotation. We compared minimum, strip, and no-tillage systems undergoing variable to uniform rate application. Grey WFs are assessed based on a field dataset using yield maps data, soil texture, and crop operations field. Leaching and associated grey WFs are assessed based on application rates and various environmental factors. Yields are measured in the field and recorded in a precision map. The results illustrate how precision agriculture combined with soil conservation tillage systems can reduce the grey water footprint by the 10%. We assessed the grey Water Footprint for all the field operation processes during the three-year crop rotation

Micronutrient deficiencies in African soils and the human nutritional nexus: opportunities with staple crops

A synthesis of available agronomic datasets and peer-reviewed scientific literature was conducted to: (1) assess the status of micronutrients in sub-Saharan Africa (SSA) arable soils, (2) improve the understanding of the relations between soil quality/management and crop nutritional quality and (3) evaluate the potential profitability of application of secondary and micronutrients to key food crops in SSA, namely maize (Zea mays L.), beans (Phaseolus spp. and Vicia faba L.), wheat (Triticum aestivum L.) and rice (Oryza sativa L.). We found that there is evidence of widespread but varying micronutrient deficiencies in SSA arable soils and that simultaneous deficiencies of multiple elements (co-occurrence) are prevalent. Zinc (Zn) predominates the list of micronutrients that are deficient in SSA arable soils. Boron (B), iron (Fe), molybdenum (Mo) and copper (Cu) deficiencies are also common. Micronutrient fertilization/agronomic biofortification increases micronutrient concentrations in edible plant organs, and it was profitable to apply fertilizers containing micronutrient elements in 60–80% of the cases. However, both the plant nutritional quality and profit had large variations. Possible causes of this variation may be differences in crop species and cultivars, fertilizer type and application methods, climate and initial soil conditions, and soil chemistry effects on nutrient availability for crop uptake. Therefore, micronutrient use efficiency can be improved by adapting the rates and types of fertilizers to site-specific soil and management conditions. To make region-wide nutritional changes using agronomic biofortification, major policy interventions are needed

Interest of site-specific pollution control policies

Owing to increasing environmental concerns the current trend is to bend technical production systems in order to adapt them to the specific characteristics of the milieu and diversify them. Inherent to such dynamics is the issue of how to design the accompanying environmental policies. Theoretically, spatially targeted environmental policies are considered optimal, since economic agents tune their efforts according to the sensitivity of the milieu where they operate. But, according to empirical analyses, this advantage is undermined by the high cost of implementation, monitoring and enforcement. This paper outlines the conditions required for site-specific policies to be effective at least cost. Our starting point is the nitrate pollution of water from agriculture, which varies according to climate, soil type and agricultural production system. Farm management practices enabling to reduce pollution depend on this variability. An interdisciplinary study of the efficiency of differentiating the way this pollution is regulated was carried out on two sites in France. It focussed on assessing the importance of spatial variability in physical parameters and in private and social costs.NONPOINT POLLUTION; SITE SPECIFIC TECHNOLOGY; SITE SPECIFIC ENVIRONMENTAL POLICY; ABATEMENT COST; TRANSACTION COST

A low environmental impact system for fertirrigation of maize with cattle slurry

The applicability of an alternative system for managing and distributing cattle slurry during irrigation on maize was evaluated. An experiment was carried out by equipping a traveller boom with drop tubes and fed from a hose-reel machine. The new system was used for the distribution of the liquid separated fraction of slurry mixed with irrigation water (fertigation) on the soil surface between the rows of the crop. This system was compared with the conventional management system, utilizing a tank wagon equipped with splash plate for slurry application and a fixed irrigation system for irrigation. Analysis on leaching water samples indicate that the quality of percolation water is better due to a reduction in nitrate nitrogen losses. Besides, this alternative technique reduces the emissions of ammonia in the air and consequently the diffusion of ammonia in the atmosphere

Soil Nitrogen: research and extension

These are the proceedings of the 4th QLIF workshiop with contributions of several European soil and nitrogen researchers

Nitrogen loss assessment and environmental consequences in the loess soil of China

Attention is focused on fertilizer nitrogen loss and the environmental consequences in Shaanxi Province in loess region of China, including N losses to the atmosphere via ammonia volatilization, nitrification and denitrification, N losses to groundwater by leaching, and crop uptake by roots. Three soils were selected, Entisol, Anthrosol and Luvisol from north, central and south Shaanxi, respectively. Nitrification and NH4+ fixation were measured using a closed chamber method in the laboratory. Denitrification was tested in the laboratory with intact soil cores, C2H2 inhibition techniques. N2O emission was assessed via in situ measurement of N2O in the soil profile and at the soil surface in field experiments. Fertilizer use and crop yields obtained by the farmers were investigated on a large scale in Shaanxi Province. Transformation of fertilizer NH4+ to NO3- was within nine days in the Entisol and Anthrosols, but it took 40 days in Luvisol due to NH4+ fixation by clay minerals. In the pot experiment open to the wind and sunshine with different water content, applied N fertilizer recovery was 74.2% for the Luvisol and 61.3% for the Entisol. The results for the Luvisol showed lower nitrogen recovery as initial soil water content increased. When the fertilizer was incorporated, the recovery was 91.6% at 8% and 68.9% at 28% water content. Recovery increased with increasing soil clay content. Large amount of nitrate was accumulated at 200-400 cm depth in the soil profile and accounted for 362-543, 144-677 and 165-569 kg N ha-1 in terrace and bottom land in north Shaanxi, terrace land in Guanzhong and south Shaanxi, respectively. N2O measurements also showed that N2O spatial variation in the profile could be ranked as, 10 cm < 30 cm < 150 cm < 90 cm < 60 cm. Temporal variation was correlated with rainfall or irrigation. Closed chamber measurements or calculations from profile concentrations resulted in N2O emission of less than 1 kg N2O ha-1 y-1. An investigation showed that soil fertility in the Guanzhong area is high, but yield has not increased with increasing N fertilizer application during the last five years. Over-application of N fertilizer was very common in the Guanzhong area and ranged from 100 to 382 kg N ha-1 for wheat and from 106 to 530 kg N ha-1 for maize. The results of the experiments indicate that the N fertilizer recovery efficiency is about 30% and the consequences of N losses are seriously threatening the environment by leaching to the groundwater and by denitrification to the atmosphere

Are EU spatial ex ante coexistence regulations proportional?

The EU is currently struggling to implement coherent coexistence regulations on genetically modified (GM) and non-GM crops in all member states. While it stresses that any approach needs to be “proportionate to the aim of achieving coexistence”, very few studies have actually attempted to assess whether the proposed spatial ex ante coexistence regulations (SEACERs) satisfy this proportionality condition. In this article, we define proportionality as a functional relationship which is weakly increasing in the incentives for coexistence. We propose a spatial framework based on an existing landscape and introduce the new concept of shadow factor as a measure for the opportunity costs induced by SEACERs. This enables comparing the proportionality of (i) rigid SEACERs which are based on large isolation distances imposed on GM farmers versus (ii) flexible SEACERs based on pollen barrier agreements between neighboring farmers. Our theoretical and empirical findings argue for flexibility as rigid SEACERs violate the proportionality condition and, hence, are not consistent with the objectives of the EU.policy analysis, GIS, shadow factor, Agricultural and Food Policy, Crop Production/Industries,