The surprising way to reduce pesticides

A new approach to reducing the use of pesticides in growing food: instead of making efforts to get rid of weeds, farmers simply let them grow among the plantation trees, thus significantly reducing the use of pesticides and the potential for harm to the public and the environment

By Maya Falah, Angle, Science and Environment News Agency

It's hard to escape lately from the fear of pesticides. After decades of trying to convince us that fruits and vegetables equal health, recently more and more studies and bodies Warn of the health hazards that in prolonged exposure to pesticides, and especially from their residues that may be found in our food.

When you add to that the herbicides and pests to which we are exposed at home, in the city parks and sometimes even in the courtyards of schools and kindergartens, realize that our and our children's exposure to pesticides may be greater than we would like to think. And this has serious consequences: among the possible health effects of pesticides are Different types of cancer, Hormonal system disorders and fertility problems, Risk of getting Parkinson's, Damage to IQ and more. And since these dangers also exist in prolonged exposure to low levels of pesticides and not necessarily in a single exposure to a substance in high concentration, it is difficult to assume that any of us is out of danger.

But it is important to remember that this is not a decree from heaven: in Western countries - and in Israel - there are laws and regulations aimed at limiting the use of these substances and trying to ensure their safe use, such that the amount of exposure to them will be reduced. The Israeli standard for pesticide residues determines which substances are allowed to be used in the various crops, so that there will be no danger to humans or the environment. The established regulations take into account, among other things, the food basket, the Israeli diet and the consumption patterns of the general public, with an emphasis on vulnerable groups such as children and the elderly.

The Ministry of Agriculture is currently promoting a change in the policy on the use of pesticides in fruits and vegetables, in the framework of which the possibility of participating in the European Union tests, which examines the possibility of banning the use of hundreds of pesticides at the end of 2017, is being examined. A lot of pesticides and the registration of about 40 percent of all active ingredients was cancelled.

Along with all of this, it is possible that in order to reduce the exposure to pesticides, something needs to change in our perception as well - we, who see insects and weeds as bad damage and declare war on them whenever we see them raise their heads. Now, through a new approach promoted at the erosion research station in the Ministry of Agriculture and Rural Development, it is possible to reduce the use of pesticides in agriculture, especially herbicides, by tens of percent.

A peace treaty with the herbs

"The farmers' war on weeds began out of fear that the weeds would compete with the agricultural crops for resources: water, nutrients, light - this is the starting point and the logic behind the traditional agricultural approach," explains Dr. Gil Eshel, a soil conservation researcher at the erosion research station. "But farmers who used to uproot the weeds from between the rows have moved over the years to use weed killer pesticides, and so many problems have arisen, of which our increased exposure to pesticides is one of them.

"In recent years, an agricultural approach has been developing here according to which the grass does not have to be bad, but can even benefit us," he continues and explains. "And so, instead of exterminating it or fighting it, we start talking about how it can be managed, and through it try to maintain a more balanced system. As part of this approach, instead of killing the weed completely - we manage it and use it to our benefit.'

The conventional agricultural approach in the last decades was to leave completely bare soil between the rows of crops. "A farmer who had weeds growing between the rows of his orchard or vineyard was seen among farmers as a bad farmer, one whose orchard or field is neglected and not cared for properly," Eshel explains. "Nowadays we are trying to change this perception among farmers, because it seems that the complete denunciation of the weeds - whether by complete displacement or certainly by the intensive use of pesticides - has causeddifferent problems Such as soil loss, increased soil erosion and increasing amounts of runoff water that is washed away from the agricultural areas instead of seeping into the soil.'

The main factor in this approach is called "ground cover", it is proving to be very successful and is currently practiced in more and more agricultural areas in Israel - in orchards, orchards and vineyards. "In a natural system that is not cultivated by man, you don't see the ground. It is covered with vegetation or remnants of vegetation that has dried up," Eshel explains. According to the approach of covering the ground with plants, one of two methods is used: either the local herbaceous vegetation is allowed to grow under the plantation trees and its growth is regulated by mowing or trampling as needed, or other plants are sown in the area, known as "cover crops". The idea of ​​cover crops is to sow a certain crop - usually a grain or legume - not for profit, but only to cover the ground and support the main crop.

"This is a method that is mainly intended for areas with a history of intensive and long weed control, which has diluted the potential amount of weed seeds that are naturally found in the soil. The cover crop in such a case is a pioneer species, which should prepare the ground for the natural growth of grass later on. It is also good for those who still find it difficult to see weeds in the orchard and perceive them as a bad thing," Eshel explains, "Here, unlike weeds, there is a growth that is under their complete control - that they have decided exactly how much of it and where to sow. The increase in cover helps in that it creates additional competition, and actually competes with the 'bad' weeds in the plot. Sometimes the farmer uses a combination of the methods and also lets the weeds grow at the same time as the cover crop. Either way, he achieves ground cover.'

Eshel and his colleagues at the erosion research station at the Ministry of Agriculture, in cooperation with researchers from the Technion, were able to show the importance of mulching and its effect on the soil In a study they carried out in an orchard near Hadera. In the study, they compared bare soil without any mulch and mulched soil, where oats or local vegetation were sown between the rows and wood chips from the nearby forests were scattered, in order to examine how the mulch affects the amounts of runoff, water penetration into the soil, and water availability to the plant. The results of the study showed that full plant cover of the soil surface reduces by 90 percent the annual amount of rain that turns into runoff and flows away from the agricultural area. Since this runoff water - which often also contains residues of pesticides that flow from the agricultural areas - seeps into the ground and reaches our drinking sources, this is an important achievement.

Pictures for the wedding in the grass

According to the CBS reportIn 2013, herbicides accounted for about 23 percent of all pesticides used in agriculture in Israel, and there was a 9 percent increase in their sales compared to 2010. The current approach - of simply letting the weeds grow - can help, among other things, reduce the dimensions of this problem. "The transition from weed control to weed 'management' makes it possible to reduce the use of herbicides of various kinds in orchards, orchards and vineyards by very high percentages," says Eshel, "If a farmer keeps a weed-free meter around his crop and sprays it, he will still manage to reduce an order of magnitude of 70 - 80 percent of the amount of pesticides (herbicides) he uses. If he is an even braver farmer and has mechanical tools to control the grass under the tree, he can even achieve a XNUMX percent reduction."

Indeed, farmers are gradually realizing the benefits of the method. "Today there are quite a few farmers in Israel and around the world who do this successfully, as well as larger plantation and orchard companies," says Eshel, "this approach is increasingly beginning to gain momentum and enter the 'mainstream' of plantation crops. Farmers try it and see that it is good, other farmers see that it works for others and try it too. They see that in the long run they also save costs. It does take some time - usually the process of balancing the weed population in a part takes about three to four years - but in the end it pays off in all respects, even from the aesthetic point of view: we see orchards that are green from head to toe in the winter - simply beautiful. In Wasp, they use this method in their pecan and pomegranate crops, and the person in charge of the orchards says that people suddenly started coming to him to take pictures for weddings. That's how beautiful the place has become.'

"It's really very beautiful," says Assaf Tzur, the kibbutz's orchard center, which has been using the cover crop method since 2010. "The grasses in the orchards keep the continuity of the green on the ground, and when the leaves fall at all - it's really very photogenic. In the last few years I don't even have to sow the crops anymore - the cover crops grow by themselves, and in the pomegranate groves what you see on the ground in the last three years is mostly natural winter grass. You need patience, but this method works well - both in the main aspect of preventing soil erosion, and also in the aspect of reducing the use of pesticides.'

"I started using this method first and foremost for the purpose of protecting the soils against soil erosion," he says. "Every year, grooves and ditches opened up in the plantation soil as a result of rains. What is done in such a case is to cover the area with dirt, and it seems really stupid and Sisyphean to me to go and bring piles of dirt to the plantation every year, to waste days of work with tractors and shovels - just to meet this ditch again next year. It seemed to me that the most logical thing would be to prevent soil erosion from the beginning - and this method answers the problem: as soon as there is plant cover, there are roots that stabilize the soil, and then it (the erosion) simply does not happen. And it gets better and better over the years - as the vegetation becomes established, the soil absorbs the water much better. The plant cover holds the soil 100 percent, and prevents the drift. This can be seen at the beginning of the process. The reduction in the use of pesticides later turned out to be a welcome by-product of the method.'

For farmers who want to use the method, Tzur asks to adjust expectations in advance. "You have to go into it with your eyes open," he says, "otherwise you can get disappointed quite easily." This is a long-term method. It takes time for the system to stabilize and achieve most of its benefits, it doesn't happen in the first year and maybe not in the second either. It requires vigilance and yes, sometimes also the use of herbicides - which is another tool for me to use to achieve my goals. I reduce the use of it - reduce it a lot, most years I don't spray at all - but I don't give it up completely. Also from an ecological point of view - working all the time just mowing the weeds requires fuel, and it may sometimes have a greater ecological impact than spraying at the right time and with the right material. But in the end, if you have patience and vigilance - in most cases this method works very well."