The emissions of nitrous oxide (N 2 O) and leaching of nitrate (NO 3 ) from agricultural cropping systems have considerable negative impacts on climate and the environment. Although these environmental burdens are less per unit area in organic than in non-organic production on average, they are roughly similar per unit of product. If organic farming is to maintain its goal of being environmentally friendly, these loadings must be addressed. We discuss the impact of possible drivers of N 2 O emissions and NO 3 leaching within organic arable farming practice under European climatic conditions, and potential strategies to reduce these. Organic arable crop rotations are generally diverse with the frequent use of legumes, intercropping and organic fertilisers. The soil organic matter content and the share of active organic matter, soil structure, microbial and faunal activity are higher in such diverse rotations, and the yields are lower, than in non-organic arable cropping systems based on less diverse systems and inorganic fertilisers. Soil mineral nitrogen (SMN), N 2 O emissions and NO 3 leaching are low under growing crops, but there is the potential for SMN accumulation and losses after crop termination, harvest or senescence. The risk of high N 2 O fluxes increases when large amounts of herbage or organic fertilisers with readily available nitrogen (N) and degradable carbon are incorporated into the soil or left on the surface. Freezing/thawing, drying/rewetting, compacted and/or wet soil and mechanical mixing of crop residues into the soil further enhance the risk of high N 2 O fluxes. N derived from soil organic matter (background emissions) does, however, seem to be the most important driver for N 2 O emission from organic arable crop rotations, and the correlation between yearly total Ninput and N 2 O emissions is weak. Incorporation of N-rich plant residues or mechanical weeding followed by bare fallow conditions increases the risk of NO 3 leaching. In contrast, strategic use of deep-rooted crops with long growing seasons or effective cover crops in the rotation reduces NO 3 leaching risk. Enhanced recycling of herbage from green manures, crop residues and cover crops through biogas or com-Published by Copernicus Publications on behalf of the European Geosciences Union. 2796 S. Hansen et al.: Review of N 2 O emissions and NO 3 leaching from organic arable rotations posting may increase N efficiency and reduce N 2 O emissions and NO 3 leaching. Mixtures of legumes (e.g. clover or vetch)and non-legumes (e.g. grasses or Brassica species) are as efficient cover crops for reducing NO 3 leaching as monocultures of non-legume species. Continued regular use of cover crops has the potential to reduce NO 3 leaching and enhance soil organic matter but may enhance N 2 O emissions. There is a need to optimise the use of crops and cover crops to enhance the synchrony of mineralisation with crop N uptake to enhance crop productivity, and this will concurrently reduce the long-term risks of NO 3 leaching and N 2 O emissions.

The purpose of the study was to compare earthworm communities under winter wheat in different crop production systems on arable land-organic (ORG), integrated (INT), conventional (CON), monoculture (MON)-and under perennial crops cultivated for energy purposes-willow (WIL), Virginia mallow (VIR), and miscanthus (MIS). Earthworm abundance, biomass, and species composition were assessed each spring and autumn in the years 2014-2016 using the method of soil blocks. The mean species number of earthworms was ordered in the following way: ORG > VIR > WIL > CON > INT > MIS > MON. Mean abundance of earthworms decreased in the following order: ORG > WIL > CON > VIR > INT > MIS > MON. There were significantly more species under winter wheat cultivated organically than under the integrated system (p = 0.045), miscanthus (p = 0.039), and wheat monoculture (p = 0.002). Earthworm abundance was significantly higher in the organic system compared to wheat monoculture (p = 0.001) and to miscanthus (p = 0.008). Among the tested energy crops, Virginia mallow created the best habitat for species richness and biomass due to the high amount of crop residues suitable for earthworms and was similar to the organic system. Differences in the composition of earthworm species in the soil under the compared agricultural systems were proven. Energy crops, except miscanthus, have been found to increase earthworm diversity, as they are good crops for landscape diversification.

Abstract:The aim of this study was to examine the sustainability performance of organic and low-input conventional farms with the sustainability assessment tool-RISE 3.0. It is an indicator-based method for holistic assessment of sustainability of agricultural production at farm level. Ten organic and 10 conventional farms from eastern Poland, Lublin province were assessed. According to the thresholds levels of the RISE method, organic farms performed positively for 7 out of 10 themes, while the values of the other 3 topics, biodiversity, working conditions, and economic viability, were at medium level. Conventional farms reached positive scores for 9 out of 10 themes. The only middle-performing theme was biodiversity. None of the two farm types had the lowest, problematic scores for examined themes. For the theme biodiversity and two indicators (greenhouse gas balance and intensity of agricultural production), significant differences between farming systems were found. Biodiversity performance, an important indicator of sustainability, estimated with the RISE system, was highly correlated with measured on-field weed flora and Orthoptera biodiversity of farms. High soil acidity and low crop productivity, improper weed regulation, and energy management were the most common problems in both types of farms. Working hours and wage and income levels were also assessed as being low. Recommendations to improve the sustainability of both organic and conventional farms are presented.

A growing interest in the cultivation of non-food crops on marginal lands has been observed in recent years in Poland. Marginal lands are a refuge of agroecosystems biodiversity. The impact of the cultivation of perennial industrial plants on the biodiversity of weeds and arthropods have been assessed in this study. The biodiversity monitoring study, carried out for three years, included five perennial crops: miscanthus Miscanthus × giganteus, cup plant Silphium perfoliatum, black locust Robinia pseudoacacia, poplar Populus × maximowiczii, and willow Salix viminalis. As a control area, uncultivated fallow land was chosen. The experiment was set up in eastern Poland. A decrease in plant diversity was found for miscanthus and black locust. The diversity of arthropods was the lowest for the cup plant. No decrease in the number of melliferous plants and pollinators was observed, except for the miscanthus. The biodiversity of plants and arthropods was affected by the intensity of mechanical treatments, the fertilization dose, and the use of herbicides. The biodiversity also decreased with the age of plantation.

Ecosystems are the basis of life and all human activities. Conservation of biological diversity is very important for the proper functioning of the ecosystem and for delivering ecosystem services. Maintaining high biodiversity in agroecosystems makes agricultural production more sustainable and economically viable. "gricultural biodiversity ensures, for example, pollination of crops, biological crop protection, maintenance of proper structure and fertility of soils, protection of soils against erosion, nutrient cycling, and control of water flow and distribution. The effects of the loss of biodiversity may not be immediately apparent, but they may increase the sensitivity of the ecosystems to various abiotic and biotic stresses. The combination of biodiversity conservation with profitable food production is one of the tasks of modern sustainable agriculture that faces the necessity of reconciling the productive, environmental, and social goals. "s further intensification of production and increase in the use of chemical pesticides, fertilizers, and water to increase yields are increasingly criticized, global agriculture is looking for other biological and agrotechnical methods in order to meet the requirements of global food production.