The recent Brazilian water crisis has raised questions about water management in all sectors. Agriculture was cited as one of the pivotal problems since it uses about 70% of the consumed water. The agricultural engineer Luís Henrique Bassoi says that the issue is not so simple. According to him, the agricultural sector is not responsible for such waste and can even generate a greater volume of water. Bassoi has a bachelor's degree from the Luiz de Queiroz College of Agriculture of the University of São Paulo (Esalq-USP); a master's degree in Irrigation and Drainage from the São Paulo State University (Unesp) in Botucatu, SP, Brazil; a PhD in Nuclear Energy in Agriculture (USP); and a postdoctoral degree in Irrigation and Drainage by the University of California in Davis, CA, USA. He is currently a researcher at Embrapa Tropical Semiarid, in Petrolina, Pernambuco, and Professor of graduate programs in Agronomy of the Faculty of Agronomic Sciences (FCA) at Unesp Botucatu and in Agricultural Engineering in the Federal University Vale do São Francisco (Univasf), campus Juazeiro, Bahia. Bassoi coordinates the Irrigated Agriculture portfolio of Embrapa, an instance that gathers all research, development and technology transfer projects of the company regarding the topic, and also outlines strategies to face the challenges related to irrigated agriculture. Science for life - Agriculture has been pointed out as the villain of the water crisis since it uses 70% of the available water. Do you agree that this percentage corresponds to reality? Bassoi - This is an average figure that was estimated using global data and corresponds to different situations of water use in agriculture. It does not necessarily match the national average, and there are variations between regions. However, we still need specific studies to get to a number for Brazil – 70% is an average with which researchers work today. Science for life - Why does the sector consume so much water? Bassoi - The term "consume" is not very appropriate for this context, in my opinion, as it gives a connotation that agriculture and livestock withdraw water from sources leaving it unavailable, which is not at all true. What happens is that only a small part of this water becomes "unavailable" to return to nature: the water that will be used by the plant or animal to "manufacture" agricultural products such as grains like rice, corn, and beans, or milk and meat, for example. The largest portion of water used in crops remains in the hydrological cycle, as we learned in school. Part of the water penetrates the soil, renewing the groundwater supply, another part of the water returns to the atmosphere by evaporation of the water in the soil surface and by plant transpiration, and yet another part is drained to water fountains. Note that this is very different from withdrawing water from a river for industrial production or urban use, in which some effluent must be treated to return to the environment. Because of all of this, I prefer to say that the agricultural and livestock sector consumes electricity and fertilizers but uses water to produce. "Brazil has nearly six million irrigated hectares, but we have the potential to get close to 30 million." Science for life - What is the importance of irrigation? Bassoi - First, it must be said that in certain areas it is impossible to produce without irrigation, as in the semi-arid. In the semi-arid it is impossible to achieve commercial agriculture that generates employment, income and development without irrigation. In general, the production of an irrigated area can be up to three times greater than a non-irrigated area, depending on culture and site. Therefore, irrigation is directly linked to the amount of food, fiber and bioenergy that we want to produce. Conservationist measures must be adopted to increase the availability of water and help agriculture to use it well, instead of closing the taps of rural areas, as has been proclaimed lately. Science for life - What are the consequences of "closing the taps" in rural areas? Bassoi - All producers use water, whether they are small, medium or large. And agribusiness covers all groups. Smallholders who market their production are also part of the agribusiness and will be the first to suffer if they cannot use water. Given this fact, it is possible to realize that without water there will be no production, income or employment for those working in rural areas, and there will be no agroenergy, fibers and especially food for those who live in the cities. Think about the production of vegetables, for example, which are crops that depend on daily irrigation. Without water, these products will be the first to disappear and to become more expensive. The impact on the national economy would also be terrible because of the influence that agribusiness has on the Brazilian gross domestic product (GDP). I must emphasize: we are not only referring to large producers: smallholders, related to essential crops, such as some vegetables, fruits, and our precious beans, will also suffer if water is cut from rural areas. Science for life - What is the responsibility of the agricultural sector in the water crisis? Bassoi - The water crisis is the result of two factors. The first is the occurrence of rain below the expected in recent years. Since 2010, according to data from weather-related institutes, the average rainfall recorded in the country is below the historical average in various parts of Brazil. There was also an aggravation between the end of 2014 and beginning of 2015, when there was an atmospheric blocking, as reported by the Observatory on the 2014-2015 Crop Year. The other factor is the lack of planning, which could have helped to face this problem even with the declining rainfall indexes. Science for life - How can we solve this issue? Bassoi - First we need society's awareness, as a whole, concerning the fact that we need to use water better. It is important, for example, to control the water consumption preventively rather than use it as the last measure. We must ration while we have water. After it is over there will be nothing to ration. Preventive measures are less expensive and less traumatic. "...with planning and the adoption of technologies that promote the efficient use of water, it is possible to reduce losses." Science for life - Is there a lot of irrigation in Brazil? Bassoi - Brazil uses little irrigation. This is because some regions still require an infrastructure for water and electricity distribution. In addition, training and technology transfer for irrigation are not widely available. Today, the country has nearly six million irrigated hectares, but we have the potential to get close to 30 million hectares, that is, the area could be five times bigger. An expansion like this also would result in the expansion of agricultural and livestock production and productivity, and the consequent increase in the supply of fiber, bioenergy and food, whether for human and animal consumption, or for processing and industrialization. It must be remembered that Brazil plays an important role as a food supplier not only for the domestic market but to the whole world. The country is one of the main actors in food and agricultural raw materials supply to the world. Irrigation will help to improve this scenario. It is time to question: what will be the cost of not using irrigation? The biggest burden will be giving up Brazil's agricultural vocation. We have land and solar energy as well as water availability in abundance, but it is necessary to rationalize the use of natural resources and invest in efficiency. Without water, there is no agriculture. The national irrigation policy (Law 12,787, 2013) should aid the planned increase in irrigated area and agricultural productivity, and encourage the capacity-building and training of human resources for the practice of a rational and efficient irrigation. The entire society can reap great benefits from it.. Science for life - Is it possible to have irrigation water even with a regime of reduced rainfall? Bassoi - Even with a reduction in the water supply, it is possible to obtain good productivity. Losses in times of water scarcity are inevitable. For many parts of the country, there is little rain forecast for the first half of this year, so it is possible that there will be crop failure. However, with planning and the adoption of technologies that promote the efficient use of water, it is possible to reduce losses. For example, the judicious application of water, considering factors such as the crop type, amount of water in the soil, crop evapotranspiration, among others. Precision agriculture, which is reaching more supporters in Brazil, can also assist the irrigation management, which is nothing more than the use of criteria to define the amount and time of irrigation. Precision agriculture takes into account variations in soil and plant in the agricultural area. Thus, in some parts of this area smaller or larger amounts of water can be used, instead of applying the same amount in the whole area. This helps to save water and increases the efficiency of water use. Science for life - Are producers trained to irrigate? Bassoi - We can find many producers who are qualified. Yet we know that the number must be increased. There is great demand for irrigation training in Brazil. Localized irrigation (drip and micro-sprinklers), for example, has increased mainly in fruit tree orchards, but there is still much expansion to be done. The subsurface drip irrigation has been used with good results in sugarcane and coffee plantations, for example. The central pivot allows for the efficient irrigation of large areas, something that is essential for crops that require large-scale production, such as grains, for example, to be profitable. Such good news about irrigation needs to be spread.. Science for life - How can farms collaborate with the rural and urban water supply? Bassoi - Rural properties can produce water. Basically, producing water means adopting conservation practices that increase the amount of water that infiltrates into the soil. In simple terms, this is achieved when maintaining the maximum amount of water on the property without letting it seep out. Thereby, water ends up seeping into the ground, renewing the groundwater that supplies a reservoir, a stream, a river, that is, any local water source. These measures are known: use of terraces and "mini-dams", maintaining vegetation atop hills, around water sources, on a riverbank (riparian forest), etc. These measures also minimize erosion. The water crisis has also shown the importance of reservation, which is the saving of water with a reservoir. Until now, it was seen as a practice with greater importance in regions where there was too little rain, such as the semi-arid. We are seeing now that even regions that have regular rainfall regime also need to have a water reserve. In rural areas, water reservoirs can be constructed so that the water can be used by one or more farms, especially during droughts. This can decrease the water withdrawal from fountains that are also used for urban or industrial supply. But it is important to note that all sectors should use water rationally. It is a collective responsibility of the entire civil society. "...it is possible to build reservoirs without causing water shortages for other users." Science for life - If building reserves is so important, why don't people invest more in reservoirs in Brazil? Bassoi - It is an important issue that deserves more discussions. There is a wrong idea about reservoirs because a lot of people consider that they could lead to water shortages for those who are further down the road, that is, downstream. This needs to be better explained to the population. By making use of integrated management and planning, it is possible to build reservoirs without causing water shortages for other users. This requires studies to determine the appropriate locations for reservoirs, the amount of water to be retained, outflow, the purpose of reservoirs, and other aspects. Science for life - Are there international examples of water management? Bassoi - In California, United States, people have been living for a long time with low hydric availability, big population, and most of the agriculture is irrigated. A wide network of reservoirs and canals ensures water supply for all users. The population has daily access to information on local or regional news, or on websites, about the level of the reservoirs. The population is informed by authorities about the need for the rational use of water in all sectors. Other good examples are Spain, Australia, and Israel. Once again I would like to stress that the key to success in this matter is planning and the integrated management of water resources. Science for life- What is the integrated management of water resources? Bassoi - A common situation can illustrate this. If the water of a river or reservoir is used for power generation, irrigation, and urban supply, there must be a common agreement related to how and when each sector requires water, as well as to establish the limits, and in case of a crisis, determine the sectors that will have priority. There is also the issue of sustainable management of water resources, which is basically the need of maintenance of quantity and quality of the water. The Brazilian federal law 9,433, 1997, which is known as the Water Law, addresses this matter. •