Best practice manual (BPM): Conversion from arable land to grassland mitigating soil erosion Cluster 3 Final version 19.10.2018 Project co-funded by the European Union funds (ERDF, IPA) Contents 1. INTRODUCTION ......................................................................................................................... 3 2. SOIL EROSION RELATED ISSUES IDENTIFIED ON TRANSNATIONAL LEVEL ......... 4 3. CONVERSION TO GRASSLAND AS A SOIL EROSION MEASURE ................................... 7 3.1. Conversion of risk fields and field parts – greening strategies ............................................................. 7 3.2. Grassed waterways ............................................................................................................................. 8 3.3. Grass strips and other protective strips ............................................................................................... 9 3.4. Buffer strips along water bodies ........................................................................................................ 11 4. METHODS TO IDENTIFY RISK AREAS FOR CONVERSION TO GRASSLAND ......... 12 5. EXAMPLE OF PRACTICAL IMPLEMENTATION - POTENTIALS FOR CONVERSION TO GRASSLAND IN BRNO PILOT AREA ................................................................................... 15 6. CONCLUSION ............................................................................................................................ 25 2 Project co-funded by European Union funds (ERDF, IPA) 1. Introduction Simply said, conversion to grassland is the most effective soil erosion prevention in steep areas of arable land. High quality afforesting can be even more effective, but it is much harder to implement and it means complete structural changes in the landscape. Conversion to grassland is not always preventing against pluvial floods, it effectively supports retention only for low intensity rainfalls. For extreme events (of low occurrence) the roughness of the grassed surfaces is low to stop rapid flow accumulation. On the other hands it always protects soil and potential floods are not muddy floods. As known from experiments supporting empirical soil erosion research, permanent grassland can reduce soil erosion 20 times up to 100 times more effectively comparing to arable land in typical agricultural management systems. Expressed by crop and management factor of the Universal Soil Loss Equation (USLE), comparing to cultivated fallow, the soil loss from permanent grassland is only 0,5% (C=0,005) while on arable land it typically is from 10% to 50% depending on crop rotation scheme (C between 0,1 to 0,5). But grassed areas also have to be maintained properly to reach the highest soil protection effect. Meadows are generally more protective than pastures. On pastures the cattle load has to be taken into account, and the cattle must be evenly moved from overgrazed areas to others. Details such as water sources for cattle at the streambanks can cause a lot of problems with high sediment and nutrient load into waters. Converting to grassland also means changes in structure of agricultural production and for many farmers it is not easy to implement cattle, sheep or other breeds into the farm management structure, even in areas morphologically (naturally) dedicated to grasslands and forestlands more than to arable cultivated land. Promoting a sustainable agriculture requires that farmers / practitioners apply the new agricultural practices based on the most advanced scientific knowledge technologies, especially those environmentally viable. The same way it means to maintain the land the way respecting natural conditions and origin of every place. Our main objective is to provide a wide scope of learning possibilities in the field of agriculture within the Danube river basin. 2. Soil erosion related issues identified on transnational level The main vulnerabilities in the pilot areas have been identified through each project partner activities. All the problems may not occur in all the pilot areas, but it is a possibility that in the future each country may be affected. GAP analysis of the different harmful practices was provided for entire Danube region within CAMARO-D partner countries. The analysis resulted in knowledge that the number of harmful practices related to arable and grass agricultural systems is variable within CAMARO-D countires, but generally it is quite high with impact on water and soil quality related issues. In following tables, the percentages of harmful practices relating to both phenomena are presented. Table 1: Percentage of bad practices from different land management segments contributing to water quality issues. Segments CZ SI HR DE RS BG HU RO AT Arable agriculture 80% 85% 85% 65% 90% 75% 55% 65% 95% Grass agriculture 75% 70% 70% 85% 80% 65% 60% 80% 70% Table 2: Percentage of bad practices from different land management segments contributing to soil functioning. Segments CZ SI HR DE RS BG HU RO AT Arable agriculture 55% 40% 85% 60% 100% 80% 60% 90% 55% Grass agriculture 60% 65% 85% 70% 85% 80% 40% 90% 65% Identified most frequent risk practices in arable agricultural and grass agricultural are listed in following table. Already from these three most frequent practices listed we see, that risk practices in agricultural lands in Danube are frequently related to soil erosion by water. Another table presents ten most frequent risk practices in CAMARO-D region on arable lands, and here we see, that all 10 most frequent practices contribute to higher soil erosion risk. 4 Project co-funded by European Union funds (ERDF, IPA) Table 3: Most frequent risk practices in arable and grass agriculture in Danube countries SEGMENT NO. DESCRIPTION FREQUENTLY USED ARABLE 3 Intensive plant production, regardless of soil and SI HR HU AGRICULTURE water conservation 4 Heavy machinery intensive use (soil compaction) CZ DE AT 18 Lack of inspection and control of SI RS BG manure/fertilizer/pesticide application GRASS 22 Practice of keeping cattle indoors in longer period SI HR RS BG AT AGRICULTURE and decreased number of grazing animals in total 23 Drainage of water contaminated from inadequate HR AT storage or application of manure on arable land 28 Management of protected areas; subjects of RS BG protection Table 4: Ten most frequent risk practices on arable lands in Danube countries (sorted by frequency of use) DESCRIPTION USED USED FREQUENTLY NORMALLY INTENSIVE PLANT PRODUCTION, REGARDLESS OF SOIL AND WATER SI HR HU CZ DE RS BG RO AT CONSERVATION HEAVY MACHINERY INTENSIVE USE (SOIL COMPACTION) CZ DE AT SI HR RS RO LACK OF INSPECTION AND CONTROL OF MANURE/FERTILIZER/PESTICIDE SI RS BG HR DE HU APPLICATION SUBSIDY DRIVEN PRODUCTION – TECHNICAL CROPS CZ BG HU DE BG MASSIVE APPLICATION OF PESTICIDES HR RS BG CZ HU INAPPROPRIATE MANURE MANAGEMENT HR AT CZ SI DE RS HU RO AT BURNING OF STUBBLE AFTER HARVESTING RS BG RO HR MONOCULTURE PRODUCTION OF PLANTS WITH LOW SOIL CONSERVATION CZ HU HR DE RS BG EFFECT CULTIVATION OF ARABLE LAND WITH NO BUFFER ZONES ALONG WATER HR DE CZ SI RS HU RO COURSES FERTILIZATION WITH MINERAL FERTILIZERS MAINLY (NO MANURE OR OTHER RS BG CZ SI HR HU RO ORGANIC FERTILIZATION) LOW LANDSCAPE FRAGMENTATION (MEAN SINGLE PARCEL SIZE (HA)) CZ RO HR BG HU NO PESTICIDE CONTROL SI RS HR BG HU IMPROPERLY USED FERTILIZERS CAUSE DIFFUSE WATER POLLUTION HR CZ SI DE BG RO In eroded areas, soil productivity is reduced due to organic matter and nutrients being carried away, thus erosion plays a crucial role in the organic matter decline of soils. Intensive plant production regardless of soil and water conservation, inadequate handling and application of pesticides and fertilizers and cultivation of arable land with no buffer 5 Project co-funded by European Union funds (ERDF, IPA) zones along water courses are recognized as major problems of agricultural land management in relation to the water conservation. Even though pesticides and fertilizers play an important role in agricultural production, reducing the adverse effects of weeds, diseases and pests on crop yield and quality and enhancing crop production, over- fertilization or inappropriate use of pesticides can primarily result in degradation of physical, chemical and biological features of soil and consequently can negatively affect both water quality and quantity. The use of heavy machinery within intensive agricultural areas leads to surface and subsoil compaction and thus increases surface runoff and can also influence water quality. The causes of soil compaction are the intensive treatment and driving on soils especially during unsuitable times (e.g. too high humidity). This leads to a decrease in the pore volume, in particular of the coarse pores, and affects the entire water transport, the infiltration of rainwater through the soil to the groundwater is impeded, the surface runoff is increased and soil erosion intensified. Thus fertilizers and pesticides get into adjacent water resources (e.g. rivers). The percentage of energy crops such as corn used for energy production is increasing. Due to the long phases of bare soil during cultivation, increasing corn production is especially problematic. Generally, the problem with soil erosion on arable land was identified in every CAMARO- D country. The situation varies in developed and less developed countries concerning use of heavy machinery but main difference is among the former eastern countries, where massive collectivization of agriculture took place in 20th century. In CAMARO-D region