3.1 Pesticide-based crop protection method

The main objective of classical agricultural production is to maximize the yield per unit of agricultural area. In order to achieve this goal, classical agriculture consumes enormous quantities of non-renewable natural resources and energy in its production process, as well as various types of agrochemicals - pesticides, mineral fertilizers.

Pesticides are chemical compounds or mixtures that are used to eliminate, control and destroy the plant pests and other pests. Unlike most pollutants that are introduced into the environment without a specific goal, pesticides are introduced with the intention of helping humans by increasing their nutritional yield, protection of the environment in the "fight" against harmful microorganisms and numerous pests. The impact of pesticides on biocenoses and the environment as a whole is very complex and diverse.

On the other hand, the rapid increase in population on planet Earth and the need for sufficient amounts of food still maintain the concept of conventional agriculture as a leader in agricultural production. It is very important that during the growing season and storage of the products and food produced that they are preserved, which means that the removal or control of harmful organisms is necessary. Damage to cultivated plants is caused by: insects, mites, nematodes, snails, rodents, some species of birds as well as pathogens: fungi, bacteria, viruses, phytoplasmas, rickettsia... Also, as a result of changes in climatic conditions, as well as approaches to weed control in recent decades (pre-em, post-em herbids), changes in the composition of the weed flora have been noticed in both ruderal habitats and arable soil. The dominant presence of close-knit thermophilic species and large-seeded broad-leaved weeds are recorded in the open ground. Drought tolerant weeds with deep roots and large seeds, then weed species that have developed resistant forms in some areas, such as perennial weeds are increasingly dominant, namely Sorghum halepense, Cirsium arvense, Convolvulus arvensis, Ambrosia artemisiifolia and others.

Extremely developed trade routes, agricultural trade, the introduction of new cultivated plants, often difficult to adapt in the new environment, have led to the introduction of many new pests, such as Diabrotica virgifera (corn rootworm), Tuta absoluta (South American tomato miner), Drosophilla suzukii (fruit fly), Pepino tomato virus, Scaphoides titanus (cicada, vector golden yellow grapevine), and others, and force the search for a pesticide application.     

In the world of agriculture, according to the World Food Organization (FAO), losses from various pests in plant production are about 28%, which clearly indicates that the use of pesticides - plant protection products, is necessary in order to reduce losses and ensure safe production.[1] On the other hand, pesticides pose a certain risk to humans and the environment, so the aim is to minimize this risk in order to produce healthy food.

Proper application of pesticides is the basis for successful plant protection and environmental protection, which contributes to better pesticide efficiency as well as economically justified application. For this reason, proper application of pesticides, among other things, involves:

• Application in accordance with pesticide registration
• Application in accordance with the declared instructions for use
• Application in accordance with the principles of good agricultural practice and integral plant protection
• Used in a way that does not endanger human and animal health and unnecessarily increase their exposure to plant protection products
• Application in a way that will not end danger the environment.

Often a major contribution to the protection and conservation of the environment can be achieved by implementing appropriate measures in the protection of cultivated plants such as:

• Reducing environmental pollution through rationalization of pesticide use;
• Application of pesticides in accordance with the requirements of the GAP (Global Agricultural Practice) chemical application policy;
• Compliance with national and international legislation regarding the application of pesticides in the protection of cultivated plants and forests;

In order to protect and conserve the environment, alternative solutions will be used, within the possibilities, in the application of pesticides for the protection of cultivated plants or by combining the application of pesticides and other methods.

[1] Forgić, Gordana (2014): Proper application of pesticides as a basis for successful plant protection and environmental protection, PSSS „Sombor“ doo, Sombor

3.2 Impact of pesticides on soils and alternative methods

The term "fate of the pesticide in the environment" means all processes of movement and transformation, and the most significant are occurring in the soil, due to the potential duration and effects they can produce. Whether they reach the soil directly or indirectly, the fate of pesticides depend on the interplay of a number of complex physicochemical processes. The fate of pesticides in the environment is influenced by processes that can be grouped into three parts:

• adsorption (binding of pesticides to mineral and organic soil matter)
• degradation (chemical, photochemical and microbiological)
• transport (movement of pesticides in the environment - evaporation, flushing, rinsing and adoption by plants)

After application of the pesticide preparation, the molecules of the active substance remain in the place where they are applied for a while, and then under the influence of air or water they can be transported to the atmosphere (evaporation), to deeper layers of soil (flushing) or laterally to the surface of the soil (rinsing). Flushing is the most important process from the mentioned processes from the point of view of environmental protection, because it represents a potential danger of groundwater pollution. This process represents the vertical displacement of compounds by the soil profile. Rinsing is the horizontal movement of pesticide molecules across the soil surface.

Reducing the use of agrochemicals, especially plant protection products, pesticides, in order to achieve successful protection of cultivated plants come down to the application of preventive and repressive measures to prevent the emergence and suppress diseases, pests and weeds.

Preventive measures mean eliminating the conditions for the development of harmful organisms and ensuring the good vitality and resistance of the cultivated species. Among the preventive measures, the following can be distinguished: reionization of plant species, selection of tolerant and resistant genotypes of varieties and hybrids, use of healthy, declared seed and planting material, proper manipulation of seed and planting material, adequate fruiting, maintenance of favorable water regime of cultivated plants, preservation of biological diversity...

Mechanical measures include various procedures for the physical removal of harmful organisms, the setting of hunting and pheromone traps. These measures aim to preserve the the cultivated plants, with the aim of productive and profitable agricultural production.

Weed control is a measure that has the greatest impact on soil pollution and, indirectly, watercourses. For this reason, the reduction or complete absence of the application of herbicides, in order to protect crops and plantations, must be comprehensive through the combination of numerous measures. All weed control measures can be divided into indirect and direct. Among indirect measures, very important is proper treatment of various wastes and residues in agriculture, proper cultivation and use of manure and compost, destruction of weed plants on non-agricultural surfaces and maintenance of agricultural machinery, facilities and farm yards, sowing clean seed... Direct weed control measures include the application of agro-technical measures (land cultivation, stubble cultivation, pre-sowing soil preparation, fertilization, sowing and crop rotation...), biological measures (infecting weeds with some phytopathogenic organisms or multiplying insects and mites), physical measures (use of mulch, mechanical, pneumatic and thermal measures ie flame application) and chemical measures (application of herbicides and arboricides). All these measures create favorable conditions for faster development of the crop and make it more resistant to weeds.

3.3 Eco-friendly crop management methods

Mankind has been searching the answer to the question of how to integrate agriculture into overall economic development whilst protecting the environment? The answers, in recent decades, are in the development of so-called alternative production such as: integrated agriculture, organic agriculture, sustainable agriculture, sustainable soil agriculture, biodynamic agriculture, "Slash and Burn" agriculture, urban agriculture.

An integral type of agricultural production is an approach to production in which pesticides and mineral fertilizers are used more rationally and expertly. Although it is one step ahead of conventional agriculture, it still has harmful effects on the ecosystem, but on a much smaller scale, than conventional agriculture.

Organic farming is also known to many as organic production because it is based on the principles of protecting human health, soil quality and ecosystems. Its production methods rely on production inputs from biodiversity without the use of synthetic inputs, products and materials. Organic farming produces food without the use of mineral fertilizers, genetically modified (GMO) organisms, pesticides and other chemical products. The entire production system develops a sustainable agroecosystem based on the natural sustainability of plants, animals and soilscapes. Both in the world and in our region, such agriculture is becoming more recognizable and economically more interesting to agriculturists and farmers.

Sustainable agriculture means the production of food, fiber or other plant or animal products using agricultural techniques that protect the environment, public health, the human community and respect the principles of animal welfare. This form of agriculture enables the production of healthy food without compromising production resources for future generations and leaves them with the opportunity to do the same. The concept of production, in crop and livestock production, is based on the non-use of toxic chemical preparations, synthetic fertilizers and (GMO) seeds. Soil, water or other natural resources are rationally used. Techniques are applied for crop rotation, soil or pasture conservation. So-called sustainable farms are being formed with the primary objective of protecting biodiversity. This form of production in the world is not yet at the level it should be. The main reason for this is poor economic profit.

Agricultural sustainable soil, as the name says, is production where the most important agricultural resource is soil. It is based on several principles that aim to exploit soil and preserve it’s quality and environment in the long term. The first key principle concerns the minimum us of the mechanical tillage, stopping erosion and preventing the loss of necessary soil moisture. The second principle is similar to the first, but applies only to the surface layer of soil and the management of the so-called top soil, where an attempt is made to create a permanent organic cover that can allow the growth of organisms by decomposing organic matter in the soil structure, which is desirable for increasing the high level of organic matter, thus creating a fertilizer in the soil. And the third principle is based on the practice of crop rotation, with more than two types of cereals as rotary crops that act as natural insecticides and herbicides against pests and individual crops.

Biodynamic agricultural production is based on Steiner's thesis on the existence of a "livelihood" in agricultural crops and soil, and each estate or farm should be a complete system and a particular balanced organism. This form of agriculture completely eliminates cultivation in monoculture. Biodynamic farm uses all production methods as in organic production. This means that no pesticides, herbicides or other protective products are used. Grassing is accelerated, composting is done, plant compatibility is created, crops and livestock are integrated, and soil is plowed and cultivated with minimal use of mechanization. It involves different ways of preparing soil and compost and using the astrological calendar to determine the time of planting and harvesting. More specifically, the moon sowing calendar is used.

One brand new concept, that we are not interested in in our region is the so-called “Slash and Burn” production. There is, realistically, no need for it because the concept of "slash and burn" is characteristic of almost all tribes of the tropical zone and rain forests, where a smaller area in the forest is deforested, after which the destroyed vegetation is ignited and the ash that remains is fertile fertilizer, which increases pH of the soil for a maximum of 3 years at a time. Before artificial fertilizers were available, fire was one of the most widely used methods of improving soil characteristics.

The reduction of arable soil and the increased demand for food have led to this, for our conditions, a new concept of agricultural production, the so-called urban agriculture. On tops of buildings, abandoned buildings and halls, or in private gardens, every piece of soil is used to grow environmentally friendly fruits and vegetables. In developed countries, so-called commercial greenhouses are increasingly appearing in residential buildings owned by companies that are distributing these greenhouse products to a nearby market under the name "fast and fresh". The growing presence of architectural plans, which pay great attention to the development of green vertical gardens in large urban regions, shows that such agriculture has a sustainable concept in the future.

One of the solutions to reduce environmental pollution (soil, water, air), and as part of its activities in agricultural production, lies in the application of Good Agricultural Practice (GAP). Good agricultural practice is based on the control of critical points and the quality of products given under World Health Organization regulations. Benefiting from the good agricultural practice are: small, medium and large producers, through the added value of all products and easier access to markets, consumers, through better quality and healthier food, like everyone else through a better environment. The concept of good agricultural practice means using the natural resources on sustainable principles to produce safe, health-safe food and other agricultural products, with economic viability and social stability.

The principles of good agricultural practice define the parameters and values that must be respected within the production system and periodically controlled by the supervision institutions. Good agricultural practice defines way of operation and production for each production system, always respecting the specifics of a given agro-ecosystem.

The basics of good agricultural practice include principles from eleven areas relevant to production: soil, water, agricultural production, crop protection, livestock farming, livestock health, livestock welfare, product harvesting, processing and storage on the farm, energy and waste management, welfare, health and human security, living world and landscape.

One of the most important areas of Good Agricultural Practice is the soil. That is because the physical-chemical properties and biological activity of the soil are key to maintaining agricultural productivity. Soil management enables minimization of loss of soil quality, then losses by erosion, runoff and drainage of surface and groundwater. The physical and chemical structure and biological activity of the soil determine its fertility and are important for maintaining soil productivity. Maintaining and enhancing soil fertility, among other things, is achieved by minimizing the loss of soil particles and nutrients through erosion, runoff and their infiltration into groundwater. Such losses represent inefficient and unsustainable soil management as a natural resource. Sustainable agricultural production tends to increase the biological activity of the soil and protect the surrounding flora and fauna. Good agricultural practice in terms of soil management implies:

• Production management within soil potential, while recording the inputs and outputs of each organizational unit;
• Maintenance and improvement of organic matter in the soil, using appropriate crop rotation and rational mechanical tillage;
• Maintenance of plant cover to reduce the harmful effects of erosion;
• Application of agrochemicals of organic and inorganic fertilizers in adequate quantities, expiry dates and methods that meet agro-technical requirements ensuring human health and healthy environment

One of the leading principles of Good Agricultural Practice, agricultural production must respect the correct selection of cultivated species and varieties with appropriate crop rotation in accordance with ecological conditions and market requirements, but with the preservation of soil fertility and implementation of all preventive and precautionary measures.

Also, one of the fundamental principles of Good Agricultural Practice is crop protection. Maintaining good crop health requires a long-term risk management strategy, using all biosecurity measures (sorts resistant to pests and diseases, crop rotation, natural corridors for good insects and minimal use of pesticides and other chemicals) is the basis for environmental protection.

3.4 Overview of management of plant protection measures in the Zajecar and Vidin

Zajecar district

In the area of Zajecar's administrative district, more than 98% of the agricultural soil is cultivated by agricultural holdings, with the remaining being produced within three companies cultivating over 3000 hectares. Crop and fruit production takes place on the parcels of the Agricultural Property "Zaječar" operating within the Agromarket Group, arable, fruit and livestock production on the parcels "Delta Agrar" Zaječar, within the "Delta Holding", and crop production in the Agricultural Property "Salas" in Salas. These three companies employ over 10 agricultural experts of various specialties. In the observed area, three agricultural expert services are also active in their field of activity: PSS "Agroznanje", PSSS "Poljoservis" and PSSS "Negotin" with more than 15 advisers, specialists in crop production. In addition, more than 25 agricultural engineers, primarily plant protection specialists, are employed in more than 20 agricultural pharmacies. In the monitored territory, activities entrusted by the state are also fulfilled by the Public Health Institute "Timok" Zaječar. Also, health inspections of cultivated plants are also carried out by three inspectors of the Plant Protection Directorate of the Republic of Serbia Ministry of Agriculture.

Vidin district

In the monitored area, the authorized organization, Montana RIEV, controls and monitors the situation and takes measures to conserve the soil. The condition of the soil involves performing inspections to preserve, improve the structure and fertility of the soil. Among other things, soil protection includes enhanced control activities:

• storage and use of plant protection products;
• protection of soil from water and wind erosion;
• soil humus levels;
• recultivation of damaged soils

Based on the established situation, "RIEV" requires measures to be taken to limit soil pollution, among which, depending on the type of soil, may be:

• the use of bio-fertilizers to stop further degradation and increase soil fertility;
• recommendation for the use of pesticides (herbicides, soil insecticides ...) that do not have a negative impact on the soil;
• introduction of organic agriculture

Table 7. Conditions for maintaining the land in good agricultural and enviromental conditions:

3.5 Good plant protection practice in the EU

EU has one of the most advanced chemicals legislation in the world called REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals). All chemical substances manufactured or imported into the EU must be registered with the European Chemicals Agency located in Helsinki. Otherwise, they can’t be sold in the EU. Particularly strict regulations apply to the most dangerous products. Companies are responsible for assessing and managing all the risks of chemicals used or sold in the EU and for providing appropriate safety advice to customers for handling of chemicals.

Is the way of using pesticides an economic decision? Sometimes it is more economical to accept a smaller presence of pathogens, pests and weeds than to treat them. However, before that, a “pest limit” for each individual pest (pathogen, pest or weed species) should be established, that is, the number of specimens or damaged area that may endanger the production of a particular cultivated plant. The time when it is profitable to use pesticides is described as an ''economic cost limit''. It is only on the basis of these two parameters, as well as consultation with a plant protection specialist, that chemical protection measures for plant protection can be taken, based on the rules of good agricultural practice. This term, good plant protection practice (GPPP) covers:

• selection, dosage and timing of application of plant protection products (pesticides) to plants and plant products to ensure effective protection with the possibility of biological and agro-technical protection measures.
• each pesticide on the EU market must be approved for certain uses by regulatory authorities, both the EU itself, and each individual EU Member State, ie the Directorate for Food Safety, Veterinary and Phytosanitary Affairs, with dosing and instructions appropriate to the conditions in CG.
• the packaging or declaration must contain basic information about usage, risks and activities to be taken in an emergency (spillage, poisoning);
• each registered farm must have a qualified professional who will provide clarification on the use and precautions to be taken;
• a record keeping system is in place, according to which the supplier and user of the pesticide must keep records of which pesticide was used, where, when, for what and in what quantity;
• permanently organizing training programs to teach farmers how to use pesticides safely, effectively and in accordance with the law.

Compliance with the GPPP rules ensures that pesticides: act effectively and have harmless effect:

• to human and animal health,
• to direct or indirect environment,
• to plants or plant products and do not accumulate in soil and in the food chain,
• to surface water and groundwater,
• to non-targeted organisms and,
• to not cause unnecessary pests that suppress both biodiversity and the ecosystem.

Proper use of pesticides ensures prevention of:

• application to other cultivated crops or other non-targeted plants,
• the negative consequences of inadequate cleaning of the sprinklers between the two uses,
• applications at an inadequate stage of plant development,
• the application of inadequate water consumption,
• uncontrolled treatment at adequate temperatures,
• inadequate protection of plants or plant products against harmful organisms or their influence.

By following the GPPP rules, it is realized that the treatment prevents human, as well as domestic animals, exposure to pesticides and respect the time interval from use of pesticides to:

• sowing or planting a crop to be protected,
• sowing or planting the next crop in crop rotation,
• the period during which persons or animals are allowed to enter the treated area (work withdrawal period),
• picking, harvesting, mowing, harvesting and processing of stored agricultural products (withdrawal period),
• use or consumption of the product.

Good agricultural practice in crop protection prevents pesticide, during the treatment, from reaching:

• water sources, watercourses, wells, lakes, sea and other surface and groundwater,
• facilities for the supply of drinking water,
• to adjacent crops and other agricultural soil,
• facilities where people live,
• facilities where domestic animals are bred or wild animals kept or other non-targeted facilities.

By following the GPPP rules that are in force in the EU countries, it is realized that at least 48 hours before the pesticide treatment that is dangerous to bees, especially during the flowering of crops, the user should inform the public, and especially beekeepers about:

• date and estimated hour of treatment,
• pesticide trade name,
• the name of the pesticide user,
• place of treatment information,
• at the time of treatment with pesticides dangerous to bees, in perennial plantings if weed species are to blooming they must be cut or in some other way prevented from coming into contact with pesticides,
• at the time of flowering crops, no systematic pesticides dangerous to bees are applied. Contact pesticides hazardous to bees at the time of flowering crops are applied only during the night hours, starting from two hours after sunset to two hours before sunrise.

A separate chapter within the GPPP is dedicated to the protection of another, very significant resource, water. It is also prescribed that the application of pesticides and their preparation:

• should not be carried out near sources of water, watercourses, wells and other surface and groundwater as well as drinking water supply facilities, but according to warnings and notices on the label;
• pesticide solution residues do not flow into water, surface and groundwater sources. The water used to wash the pesticide application device should be sprayed on the treated surface or treated as hazardous waste in accordance with the law governing waste management;
• treatment shouldn’t be done in the vicinity of water protection zones in accordance with the law which regulates water protection according to the instructions for use and on the label;
• after use of pesticides, empty containers shall be handled in accordance with the instructions on the label;
• with packaging containing pesticide residues, pesticide contaminated waste, and pesticides which have expired warranty or expiry date shall be treated as hazardous waste in accordance with the law governing waste management.