Monitoring nutrients fate after digestate spreading in a short rotation buffer area

One of the main sources of reactive nitrogen pollution is animal manure. The disposal of digestate (material remaining after the anaerobic digestion of a biodegradable feedstock) in agricultural soils could solve both the problems of soil fertilization and waste removal, but the fate of digestate in the environment must be assessed carefully before its massive utilization. To investigate whether digestate could be safely employed as a soil fertilizer, an agricultural field located in Monastier di Treviso (Northern Italy) and characterized by the presence of low hydraulic conductivity clay soils, was selected to be amended with bovine digestate. The experimental site was intensively monitored by a three-dimensional array of probes recording soil water content, temperature, and electrical conductivity, to solve the water and bulk mass fluxes in the unsaturated zone. High-resolution soil coring allowed the characterization of soil water composition over two hydrological years. Chloride, found in high concentrations in the digestate, was used as environmental tracer to track the fate of the percolating water. The study concluded that digestate could be confidently employed in short rotation buffer areas at an average rate of 195 ± 26 kg-N/ha/year in low hydraulic conductivity soils not affected by diffuse fracturing during dry periods.     

Farmers’ perception of sustainable agriculture and its determinants: a case study in Kahramanmaras province of Turkey

The primary purpose of this study was to assess in quantitative terms farmers’ perceptions of sustainable agriculture and to determine how those are influenced by different socio-economic characteristics and information-seeking behavior of the farmers. The study was conducted in Kahramanmaras province of Turkey and comprised a stratified sample of 208 farmers from four districts of the province. The farmers rated each of the 21 selected sustainable agricultural practices for importance on a 5-point scale, and the total of these ratings formed the sustainable agriculture perception index. The index score was calculated for each farmer and was treated as the dependent variable in the stepwise regression analysis procedure. The independent variables were such socio-economic characteristics as the farming system, the total and irrigated area of the farm, membership of a cooperative society and participation in village administration, and age, education, and income of the farmer; components of information-seeking behavior included use of the mass media (newspapers, radio, and television), use of the Internet, travel, and participation in farming events. The results of the study showed that the higher the socio-economic status (more frequent contact with extension services, higher education, ownership of land, etc.) and the greater the access to information, the greater the perceived importance of sustainable agricultural practices. It is concluded that if policy-makers and extension organizations concentrate on these factors, they are more likely to succeed in making farmers more favorably disposed toward sustainable agriculture.     

Evaluation of a diode laser based photoacoustic instrument combined with preconcentration sampling for measuring surface–atmosphere exchange of ammonia with the aerodynamic gradient method

We present here a novel instrument for measuring surface–atmosphere exchange fluxes of ammonia. The instrument is the upgraded version of a recently developed near-infrared diode laser based photoacoustic ammonia concentration monitoring instrument, i.e. the original instrument is supplemented with two additional sampling lines, an appropriate gas handling system and an advanced software controlling gradient measurements. As a result of these developments, ammonia concentration can be measured simultaneously at three different heights above the ground and ammonia fluxes can be calculated from these data using the aerodynamic gradient method. The instrument operates fully automatically, requires minimal maintenance and has a temperature controlled, waterproof housing which makes it suitable for measurements even under harsh field conditions. Preliminary tests on stability and accuracy were carried out during two two-week field measurement campaigns, with the three sampling inlets being placed at the same height together with the inlet of a reference instrument. The readings of the three channels agreed well (with correlation coefficients above 0.96). Comparison to reference instruments showed good stability of the photoacoustic instrument, there was no measurable zero-drift or change in sensitivity during the tests. Flux measurements were carried out during a three-week field campaign in southern Scotland over fertilized grassland with reference to a wet-chemical AMANDA instrument in gradient configuration. Ammonia fluxes calculated from the data of the two instruments agreed well. Fluxes up to 2500 ng m^?2 s^?1 were observed after fertilization. The minimum detectable ammonia flux was calculated on the basis of “virtual ammonia fluxes”, from measurements carried out with all inlets at the same height and was found to be ±60 ng m^?2 s^?1 which ensures reliable measurements above intensively managed grasslands or agricultural fields.     

Linking climate change adaptation practices with farm technical efficiency and fertilizer use: a study of wheat–maize mix cropping zone of Punjab province,Pakistan

Environmental Science and Pollution Research - Climate change is a serious threat to global agriculture and the farming community is well aware of this challenge. This is the first empirical study...