The Role of Biological Diversity in Agroecosystems and Organic Farming

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. Agricultural 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. As 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

Assessing the Sustainability Performance of Organic and Low-Input Conventional Farms from Eastern Poland with the RISE Indicator System

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

Influence of loss of biodiversity of agroecosystems on the decline of the pollinating insect population, with special concern to the honeybee

Pszczoła miodna (Apis mellifera) jest najważniejszym owadem w gospodarce człowieka oraz gatunkiem kluczowym w funkcjonowaniu ekosystemów rolniczych. Do najistotniejszych funkcji tego gatunku należy zapylanie roślin uprawnych oraz produkcja miodu. Pszczoły są bezpośrednio zależne od bioróżnorodności danego obszaru. Niektóre badania wskazują, że spadek dostępności i różnorodności roślin pożytkowych jest przyczyną osłabienia kondycji owadów, co zwiększa prawdopodobieństwo wystąpienia zjawiska wymierania rodzin pszczelich. Większość badań wskazuje na pozytywny wpływ rolnictwa ekologicznego, różnorodności krajobrazu oraz obecności w nim półnaturalnych użytków zielonych na populację pszczoły miodnej. Szczególnie negatywnym zjawiskiem w rolnictwie jest szeroko pojęta intensyfikacja, objawiająca się stosowaniem pestycydów, dużym zużyciem nawozów sztucznych, oraz brakiem roślin poużytkowych w uprawach.Honey bee (Apis mellifera) is the most important insect in the human economy and a key species in functioning of agricultural ecosystems. The most important functions of this species include pollination of crops and the production of honey. Bees are directly related to the biodiversity of the landscape. Some studies indicate that the decline in availability and diversity of crop plants is a cause of the decline in the condition of the insects, which increases risk of mass bee colony collapse. Most studies indicate the positive impact of organic farming, landscape diversity, and the presence of semi-natural grasslands on honey bee populations. Particularly negative phenomena in agriculture are the widespread perception of pesticide use, the large amount of synthetic fertilizers, and the lack of blooming plants in crops

Biodiversity of Weeds and Arthropods in Five Different Perennial Industrial Crops in Eastern Poland

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

Assessment of Resistance of Different Varieties of Winter Wheat to Leaf Fungal Diseases in Organic Farming

A change in agricultural policy in the European Union aims, among other things, to halve the use of pesticides and increase the share of organic farming to 25% by 2030. One of the challenges associated with this target will be the control of plant fungal diseases. The key methods in organic farming include the selection of less susceptible crop varieties. In order to test this method, a long-term trial of organic farming in Eastern Poland was established. In total, 41 different winter wheat varieties were grown from 2018 to 2022 and their resistance to fungal leaf diseases was monitored. Brown rust was found to be the disease causing the highest infestation towards the end of vegetation, often exceeding 80% of the flag leaf area. However, yield reductions were mainly related to the severe occurrence of leaf Septoria. Other leaf diseases such as tan spot, yellow rust, powdery mildew, and fusariosis were of little importance and only occurred at low infestations of Septoria and brown rust. The course of the weather was found to have a significant effect on disease incidence. Drought occurring in May and June significantly increased the incidence of brown rust and Septoria, while prolonged rains increased tan spot and Fusarium infestation. Greater overall infestation occurred in years with high average temperatures. Ten varieties with high resistance to foliar fungal diseases were selected and can be recommended for organic farming

Reviews and syntheses: Review of causes and sources of N2O emissions and NO3 leaching from organic arable crop rotations

The emissions of nitrous oxide (N2O) and leaching of nitrate (NO3) 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 N2O emissions and NO3 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), N2O emissions and NO3 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 N2O 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 N2O fluxes. N derived from soil organic matter (background emissions) does, however, seem to be the most important driver for N2O emission from organic arable crop rotations, and the correlation between yearly total N-input and N2O emissions is weak. Incorporation of N-rich plant residues or mechanical weeding followed by bare fallow conditions increases the risk of NO3 leaching. In contrast, strategic use of deep-rooted crops with long growing seasons or effective cover crops in the rotation reduces NO3 leaching risk. Enhanced recycling of herbage from green manures, crop residues and cover crops through biogas or composting may increase N efficiency and reduce N2O emissions and NO3 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 NO3 leaching as monocultures of non-legume species. Continued regular use of cover crops has the potential to reduce NO3 leaching and enhance soil organic matter but may enhance N2O 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 NO3 leaching and N2O emissions

Reviews and syntheses: Review of causes and sources of N2O emissions and NO3 leaching from organic arable crop rotations

The emissions of nitrous oxide (N2O) and leaching of nitrate (NO3) 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 N2O emissions and NO3 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), N2O emissions and NO3 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 N2O 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 N2O fluxes. N derived from soil organic matter (background emissions) does, however, seem to be the most important driver for N2O emission from organic arable crop rotations, and the correlation between yearly total N-input and N2O emissions is weak. Incorporation of N-rich plant residues or mechanical weeding followed by bare fallow conditions increases the risk of NO3 leaching. In contrast, strategic use of deep-rooted crops with long growing seasons or effective cover crops in the rotation reduces NO3 leaching risk. Enhanced recycling of herbage from green manures, crop residues and cover crops through biogas or composting may increase N efficiency and reduce N2O emissions and NO3 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 NO3 leaching as monocultures of non-legume species. Continued regular use of cover crops has the potential to reduce NO3 leaching and enhance soil organic matter but may enhance N2O 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 NO3 leaching and N2O emissions