Ewa Szara

The Use of Phosphorus Sorption Parameters in the Monitoring of Potential Emissions of this Component from the Arable Lands

Abstract The study assesses the usefulness of different methods of determining the sorption properties of soils in relation to phosphorus in the agricultural soils from Central Poland in terms of the risk of environmental pollution posed by this component. As a reference parameter necessary to achieve the study.s objective, the sorption capacity of soils for phosphorus determined on the basis of the Langmuir model was used. The results of the tests were used to calculate the degrees of soil saturation with phosphorus: PE-R/Smax (Psat1); PE-R/PSI36 (Psat2), PM3/AlM3 + FeM3 (Psat3); Pox/Alox+Feox (Psat4); PE-R/AlM3+FeM3 (Psat5); PE-R/ Alox+Feox (Psat6). The usefulness of these indicators for assessing the risk of phosphorus emissions from agricultural land was determined on the basis of the coefficients of their correlation with the amount of active phosphorus in the soil. The study proved the usefulness of the Mehlich-3 and acid ammonium oxalate solutions for assessing the sorption capacity and the degree of saturation with phosphorus of typical Polish agricultural soils. For identifying the risk of phosphorus leaching from the soils, the parameter that specifies the extent of soil saturation with phosphorus as determined by the Egner-Riehm test and the sorption index (PSI) obtained by equilibrating the soils with a solution containing 36 mg P dm.3 at the soil-to-solution ratio of 1:10 (Psat2) were also found useful.

Assessment of various practices of the mitigation of N2O emissions from the arable soils of Poland

Abstract This review assesses the adaptability and effectiveness of the basic practices to mitigate the N2O emissions from the arable land in the climate, soil and agricultural conditions of Poland. We have analyzed the decrease in the nitrogen-based fertilization, selection of the fertilizer nitrogen forms, use of biological inhibitors of nitrogen transformation in the soil, control of the acidic soil reaction, reduction in the natural fertilizers use and afforestation of the low productive soils. The challenge evaluating the effectiveness of mitigation practices lies in the inadequacy of the national data on N2O soil emissions in particular agrotechnical conditions. In Poland, circumstances that favor intensive N2O emissions from the arable soils occur uncommonly, as shows the analysis of the literature reporting on the country climate, soil and agricultural conditions alongside the N2O emissions from soils under various cultivation conditions. Consequently, the effectiveness of mitigation practices that relies on an extensification of plant production may be insufficient. It can be assumed that, at the doses of nitrogen fitting the nutritional needs of crops, the soil N2O emissions are low and do not meaningfully differ from the emissions from untreated soils (literature data point to limited N2O emission from arable soils treated with N doses of ≤150-200 kg N·ha-1). The effectiveness of the nitrogen fertilization reduction as an N2O emissions mitigation practice is restricted to intensive farming. A universal registry of the mineral and natural fertilization use could help identify the agricultural holdings with a potential for high N2O emission and foster a targeted application of mitigation practices. It is suggested that normalization and maintenance of the optimum (i.e. close to neutral) soil pH should become a more common practice of N2O emissions mitigation in Poland in view of the extent of arable soils acidification and the literature data that indicate elevated N2O emissions from acid soils. Application of urease and nitrification inhibitors alongside nitrogen fertilization can be considered an effective practice of N2O emissions mitigation. Owing to economic reasons the use of nitrogen fertilizers with such additives is currently limited to non-agricultural segments of plant production. Afforestation of the low productive soils offers an attractive opportunity for mitigation of N2O emissions. Whereas N2O emissions from forest soils are considerably lower compared with those from the arable ones, the literature indicates that no N2O emissions mitigation is attained through a conversion of arable land to agroforestry. Considering the current forest area of Poland (24.9% of the total area) and the plans to increase the afforestation rate (to 33% in 2050) the measurable effects of this mitigation practice will only be seen in a long-term perspective. Besides identifying and excelling the mitigation practices the authors postulate a review of the algorithms employed by the National Centre for Emissions Management (KOBiZE) for the calculation of the GHG emissions. Solutions applied by KOBiZE appear to address mainly the area - or population-related aspects and, to a much lesser degree, the actual N2O production. In this context, the effects of certain N2O emissions mitigation practices might be difficult to be taken into consideration. The application of national statistics of the use of mineral and natural fertilizers to the calculation of the N2O emissions from the arable soils might be questioned given that the N2O emissions are driven by the actual local N dose.

Model of nitrogen management on farms specializing in livestock production

Abstract The aim of this study was to determine the relationship between the efficiency of agricultural production and selected parameters of farms and data describing the flow of nutrients on the farms. An analysis model was developed for nitrogen management on farms specializing in livestock production. The study was conducted on 20 farms located in 12 municipalities of the Mazowieckie province in central Poland in 2009.2012. The model was developed using multiple linear regression analysis in accordance with the backward stepwise method. Based on the regression analysis, the farm parameters that did not determine the dependent variable were eliminated. In the end, there were 10 independent variables included in the model. The model indicates that the efficiency of nitrogen management, expressed in cereal units per 1 kg of nitrogen (CU·kg-1 N), is significantly affected by: crop rotation, the demand for purchasing animal feed, the intensity of livestock production, the nitrogen content of farmyard manure, the nitrogen doses applied in mineral and natural fertilizers, and nitrogen outflow from farms with the sale of plant and animal products. The developed model explains 70% of the variation in the coefficient of efficiency expressed in cereal units per 1 kg N.