Dryland Agriculture

Dryland farming is associated with drylands - dry areas characterized by a cool wet season followed by a warm dry season. Dry farming may be practiced in areas that have significant annual rainfall during a wet season, often in the winter. Crops are cultivated during the subsequent dry season, using practices that make use of the stored moisture in the soil.

Successful dryland farming is possible with as little as 9 inches (230 mm) of precipitation a year; higher rainfall increases the variety of crops. Native American tribes in the arid Southwest survived for hundreds of years on dryland farming in areas with less than 10 inches (250 mm) of rain.

As arable land continues to degrade and diminish, and as the Earth's population continues to spiral upward in a warming and drying world, demand will ramp up for high-yielding crops that will be productive in semi-arid and arid regions. Few C3 or C4 crop species, however, exhibit traits that enable them to be sustainably productive in dry and hot climates, particularly in nutrient-poor soils. Photosynthesis via the C4 pathway enables several crops, such as corn (Zea mays), sugarcane ((Saccharum officinarum), and sorghum ((Sorghum bicolor), to tolerate extremes in heat, but maintaining high yields depends on having reliable sources of irrigation water. The need for heat- and drought-tolerant crops is especially pronounced in arid and semi-arid regions, which cover nearly 40% of the world's land surface area. In these regions, insufficient rainfall and intense evapotranspiration act as barriers to the cultivation of many economically important C3 and C4 crops.

Although limited in number, some crop species fix CO2 through an alternate form of photosynthesis, crassulacean acid metabolism (CAM), which maximizes water-use efficiency by shifting most CO2 uptake to the night. Cooler nighttime temperatures reduce the vapor pressure gradient between their leaves and the air, resulting in markedly lower transpiration rates as compared to C3 and C4 plants. Consequently, CAM confers the ability for plants to be highly water-use efficient in hot, water-limited environments. While CAM is found in several families, approximately 7% of all plant species use this photosynthetic pathway. Most CAM plants are small and lack any apparent benefits as crops; CAM and allied traits, such as succulence, waxy cuticles, and low stomatal conductance, largely allow these plants to survive in semi-arid and arid lands. Several CAM crops exist, such as Aloe vera (Xanthorrhoeaceae), Hylocereus spp. (Cactaceae), and Vanilla planifolia (Orchidaceae), but several Agave species (Asparagaceae); pineapple (Ananas comosus, Bromeliaceae); and prickly pear cactus (Opuntia ficus-indica, Cactaceae) and other species in the genus, have been cultivated for hundreds of years for food, beverages, and fiber in hot and drought-prone regions of the world.

Given the dearth of efforts to develop and improve CAM species as crops, priority needs to be given to research on species that will yield the greatest impact in addressing human needs. On a global scale, Ananas comosus ranks as the most commercially important CAM crop. Besides being mainly grown for its fresh fruit in different parts of the world, other uses of A. comosus include alcohol, additive agents, and fiber. However, its physiology limits its cultivation to arable lowlands in subtropical or tropical areas, which only constitute 5% of the earth's total land surface. In addition, high levels of irrigation and fertilizer are required to sustain high yields of A. comosus. And while leaves can be used as a source of fiber or bioenergy, such applications will likely be only regional in scale and application given that A. comosus can only be grown in tropical regions. Moreover, climate projection models suggest that while climate change will expand suitable cropland in northern latitudes, tropical regions could become less suitable for agriculture.

Compared with Ananas comosus, Opuntia ficus-indica and related species offer more versatility as a crop due to their high productivity, ability to be grown in semi-arid lands, and diverse end uses. Largely grown in areas in Mexico, Brazil, and other parts of the world with mild to warm winters, O. ficus-indica can be cultivated for its sweet or sour fruit, young cladodes as vegetables for human and livestock consumption, and as a host plant for cochineal insects (Dactylopius coccus) for the production of valuable dyes. Besides the risks associated with widespread planting of clonal monocultures, the sensitivity of Opuntia ficus-indica to frost limits its production to areas without chilling to subfreezing temperatures. Other highly productive Opuntia species, which could be considered as crops, exhibit more cold hardiness than O. ficus-indica, but their prolific spines and glochids preclude their widespread use. In addition, Opuntia ficus-indica and other members of the genus have been found to be highly invasive in some semi-arid environments. These limitations of O. ficus-indica underscore the challenges in using it as a model CAM crop system.

Agave, more so than A. comosus and Opuntia ficus-indica, offers the greatest potential to be more extensively used as a crop in a warming and drying world. In the southwestern U.S., Mexico, and Central America, several pre-Columbian indigenous groups obtained food, beverage, fiber, medicine, and other vital products from several species within the Agave genus to persist despite living under harsh environmental conditions.

The Agave genus constitutes a large and diverse group of stress-tolerant succulents native to semi-arid regions of the Nearctic and Neotropics.

Modern society, particularly populated areas where water is severely limited, could benefit from the utilization of agaves as crops. The high productivity of several Agave species, coupled with their use of the CAM pathway, have led some to believe they can be used to resolve pressing environmental issues and energy needs. The genus also has the potential to serve as a model to determine how drought-tolerant crops could help resolve disparities between increasingly scarce resources and pressing societal needs, particularly in connecting traditional crop systems with modern agricultural approaches. This is especially the case for semi-arid regions that are prone to prolonged periods of drought, such as the southwestern U.S.. Agricultural activities consume nearly 80% of available water in the Southwest, which will likely increase due to the needs associated with growing urban and suburban populations. Demand will continue to spiral upward for the reallocation of water from agricultural and industrial operations to meet domestic needs of large population centers in these semi-arid regions. This will only aggravate the situation for farmers and producers who not only have to deal with drought-associated reductions in available water, but also challenges due to increased domestic consumption. The margin of error for cultivating conventional, high-water-use crops will increasingly become thinner, which could ultimately lead to limited food choice for consumers as well as increased compromises in food security. These risks underscore the need to focus on innovative solutions, such as the widespread cultivation of crops in areas that could be subject to widespread, severe droughts. Evaluating Agave as a model crop system will be a promising step in that direction.

Notwithstanding the potential benefits of using Agave as a model crop system, little has been done to synthesize what is known concerning its more traditional, but still modern, uses as food, beverage, and fiber, in line with its more contemporary and innovative uses in the sweetener and bioenergy industries.

(by J. Ryan Stewart

(From https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2015.00684/full)

Crops Suited and Unsuited For Dryland Agriculture

Crops grown through dryland agricultural systems must be highly drought tolerant. However, germinating seeds or rooted cuttings of these plants still require a considerable amount of water. Hence, normal water conditions must be available during the initial stages of plant growth.

A lot of experimentation goes into determination of the type of crops to be grown by dryland farming at a particular location. Besides water availability, temperature conditions, the nature of the soil, the topography of the land, and other factors act in unison to determine the success or failure of crop growth on a piece of land. It often takes years of experimentation to establish a successful crop on dryland farms.

Corn, sorghum, and millets are some of the cereal crops best suited to dryland farming. Legumes like common beans, cowpeas, and pigeon peas, leafy vegetables like cassava greens, comfrey, and leucaena, fruit vegetables like watermelons, okra, dates, papaya, cashew, olives, and tamarinds, and oil plants like owala and sunflower seed are usually suitable for growth in arid climates. Among the non-food commercial crops that can be grown in arid climates are fiber-producing plants like Sea Island Cotton and sisal, timber plants like umbrella thorn, and feed legumes and grasses like mesquite, Mother of Cacao, and Bermuda grass.

(See Dryland Crops for a discussion of each crop suitable for arid or semi-arid water regimes.

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Some very common crops are, however, completely impossible to grow by dryland agriculture, such as the food crops of rice (requiring 3,000 to 5,000 liters of water per kilogram of crop produced) and sugar-cane (1,500 to 3,000 liters of water per kilogram), and certain varieties of commercially cropped cotton (7,000-29,000 liters of water per kilogram).

The choice of crop is influenced by the timing of the predominant rainfall in relation to the seasons. For example, winter wheat is more suited to regions with higher winter rainfall while areas with summer wet seasons may be more suited to summer growing crops such as sorghum, sunflowers or cotton

CAM (Crassulacean Acid Metabolism) Photosynthesis to the Rescue

As climate change leads to drier and warmer conditions in semi-arid regions, growing resource-intensive C3 and C4 crops will become more challenging. Such crops will be subjected to increased frequency and intensity of drought and heat stress.

However, agaves, even more than pineapple (Ananas comosus) and prickly pear (Opuntia ficus-indica and related species), typify highly productive plants that will respond favorably to global warming, both in natural and cultivated settings. With nearly 200 species spread throughout the U.S., Mexico, and Central America, agaves have evolved traits, including crassulacean acid metabolism (CAM), that allow them to survive extreme heat and drought.

Agaves have been used as sources of food, beverage, and fiber by societies for hundreds of years. The varied uses of Agave, combined with its unique adaptations to environmental stress, warrant its consideration as a model CAM crop. Besides the damaging cycles of surplus and shortage that have long beset the tequila industry, the relatively long maturation cycle of Agave, its monocarpic flowering habit, and unique morphology comprise the biggest barriers to its widespread use as a crop suitable for mechanized production. Despite these challenges, agaves exhibit potential as crops since they can be grown on marginal lands, yet with more resource input than is widely assumed. If these constraints can be reconciled, Agave shows considerable promise as an alternative source for food, alternative sweeteners, and even bioenergy. And despite the many unknowns regarding agaves, they provide a means to resolve disparities in resource availability and needs between natural and human systems in semi-arid regions.

Methods Used

Dryland farming demands a great deal of effort to ensure that the soil is not deprived of moisture. Formation of soil crust at the surface is prevented by tillage to allow rainwater to seep in and reach the plant roots. Water runoff from crop fields is checked by leveling the fields and establishing bunds or contour strips. Soil water evaporation is inhibited by mulching and the planting of shelter belts of trees and shrubs. Dryland farming also involves the planting of crops in a more dispersed manner, and in less numbers overall, than what is seen in "wet" farming methods. Weeds are completely destroyed so that these insignificant plants do not compete with the crop plants for water. Strip cropping is also commonly practiced in dryland agriculture. During the fallow periods in dryland agriculture, no crops are grown in the fields to allow the soil to absorb and retain moisture and recharge their nutritional capacities.

Dry farming depends on making the best use of the "bank" of soil moisture that was created by winter rainfall. Some dry farming practices include:

Capillary Water

What is capillary water in the ground?

Trees drink from capillary water. Their instrument to drink from the capillary water is the primary root. On the picture below, you can see the primary roots going downwards to the dark soil. This soil is dark because of the water content in the capillary channels.

In soil, there are millions of vertical channels - pipes - these are called capillary tubes. Whenever there is a downpour, excess water runs underground through these capillary tubes. When it is dry, these same tubes transport water to the surface. Trees have their roots in these capillary tubes - which also contain threads of fungi which are hygroscopic (attracting water); and with their lateral roots, they soak up capillary water when it is hot and dry. This is how a tree survives heat and drought. Even in rocks, minuscule and invisible fissures function as capillary tubes.

The Capillary Principle*

Rainfall in Deserts

Even in less mild climates, there is more than enough capillary water supply in the soil for a tree to survive and grow. There is more rainfall in deserts than we think - often between 150 and 250 millimetres (6-10") per year. This is equal to 150 to 250 liters (40-65 gallons) per m2 because 1 millimeter (mm) of rainfall is equal to 1 liter of water per m2. That is 1.5 to 2.5 million liter per hectare (0.15 to 0.25 million gallons per acre). In many deserts, there is 500 mm (20") of precipitation per year; and some deserts even get up to 1000 mm! The Netherlands gets around 700 mm a year.

The problem is not the lack of precipitation, but the time it falls. In some locations, it rains for 1 month, and it remains dry for 11 months. If the wet period is too short to allow the young roots to reach capillary water, the sapling (young tree) dies. If the wet period is long enough, and the roots reach capillary water, the sapling can survive.

If we look at rocky locations (e.g. the Alps, the Rocky Mountains), or at savannas (e.g. Mali, Mauritania), then we see that enormous trees can easily grow there. Even above entrances to tunnels (e.g. the Dutch Coentunnel, the Dordtse tunnel, and the Maastunnel), enormous poplars can easily survive prolonged periods of drought, as during the summer of 2006. The soil is only six meters deep, and there is a tunnel below. Rocks or temporary drought pose no problem for trees which use their leaves to absorb condensation water. This is certainly no problem when the roots have already grown to the depth of the capillary water.

Nature can form her own environment with capillary water

If we supply the required amount of water during the early stages – when a tree is still young and its roots have not grown deep enough to reach capillary water – then trees can grow virtually anywhere. In addition, a forest creates by itself, the right conditions to stimulate and aid growth. Trees create a different and unique microclimate where they grow - i.e. they provide shade for other plants; they attract animals which distribute seeds; the soil becomes looser and richer, and it receives organic matter which is better able to hold water and nutrients. An environment slowly forms in which many different plant and microscopic species can grow. Nature has always done this without our help - changing bare rock into rich soil.

How to prevent the loss of capillary water through evaporation

The best technique to keep capillary hang water in the soil, is to add a layer of loose surface soil. During the day, capillary water evaporates because of the sun's heat hitting the soil. At night, the soil is warmer than the air; and so, the water evaporates. You can see this in two photos taken after a small test, which proves this phenomenon. The best way to stop this evaporation is by protecting the capillary column by putting a small layer of loose soil on top. 50 Years ago in Holland, when there was no irrigation, growers used an old technique to loose the top layer. This technique combined maintaining the humidity with weed control. The instrument they used for this purpose was the roller scraper.

Rainwater Harvesting

Rainwater harvesting is the accumulation and storage of rainwater for reuse on-site, rather than allowing it to run off. Rainwater can be collected from rivers or roofs, and in many places, the water collected is redirected to a deep pit (well, shaft, or borehole), a reservoir with percolation, or collected from dew or fog with nets or other tools. Its uses include water for gardens, livestock, irrigation, domestic use with proper treatment, indoor heating for houses, etc. The harvested water can also be used as drinking water, longer-dt storage, and for other purposes such as groundwater recharge.

Rainwater harvesting is one of the simplest and oldest methods of self-supply of water for households usually financed by the user.

New approaches

Instead of using the roof for catchment, the RainSaucer, which looks like an upside-down umbrella, collects rain straight from the sky. This decreases the potential for contamination and makes potable water for developing countries a potential application. Other applications of this free-standing rainwater collection approach are sustainable gardening and small-plot farming.

A Dutch invention called the Groasis Waterboxx is also useful for growing trees with harvested and stored dew and rainwater.

Traditionally, stormwater management using detention basins served a single purpose. However, optimized real-time control lets this infrastructure double as a source of rainwater harvesting without compromising the existing detention capacity. This has been used in the EPA headquarters to evacuate stored water prior to storm events, thus reducing wet weather flow while ensuring water availability for later reuse. This has the benefit of increasing water quality released and decreasing the volume of water released during combined sewer overflow events.

Generally, check dams are constructed across the streams to enhance the percolation of surface water into the subsoil strata. The water percolation in the water-impounded area of the check dams can be enhanced artificially manyfold by loosening the subsoil strata and overburden using ANFO explosives as used in open cast mining. Thus, local aquifers can be recharged quickly using the available surface water fully for use in the dry season.

Greening The Desert, by Masanobu Fukuoka

When he first saw the condition of the landscape in California he was shocked by how barren it was. Some of that, he noted, was caused by the climate, which lacks the dependable summer rains of Japan, but much of it was caused by careless agricultural practices, poor water management, overgrazing, and overlogging. Eventually he came to refer to this as California's ecological disaster. After visiting India and Africa, he got an idea of the magnitude of the worldwide ecological crises. From that time on he devoted all his energy to solving the problem of desertification using natural farming.

Mr. Fukuoka believed that most of the world's deserts were created by human activity. These ill-advised actions were based on incomplete human understanding. He felt that the deserts could be revegetated by broad-scale seeding of as many species of plants and microorganisms as could possibly be gotten together. Since conditions had been altered so drastically, it would not do to try to put things back the way they once were. By making the seeds of all the different species of plants and microorganisms available, nature would be able to take the most appropriate course given the present conditions. He refers to this as the Second Genesis. Most important, people's preconceived ideas would be left out of the decision-making process. He believed that plant quarantines should be done away with and large seed banks should be created to facilitate this effort.

Mr. Fukuoka's plan for halting desertification and his thoughts about such things as economics, politics, diet, formal education, the arts, health care, and science, which are all discussed here, proceed directly from his core philosophy, which came to him unexpectedly that morning in Yokohama when he was twenty-five years old. He saw nature as a single, interconnected reality with no intrinsic characteristics. He saw time as an uninterrupted moment of the present with past and future embedded within it.

Applying natural farming techniques in Africa (an Interview)

Robert: What have you learned in your 50 years of work about what people could do with their agriculture?

Masanobu: I am a small man, as you can see, but I came to the States with a very big intention. This small man becomes smaller and smaller, and won't last very long, so I'd like to share my idea from 50 years ago. My dream is just like a balloon. It could get smaller and smaller, or it could get bigger and bigger. If it could be said in a brief way, it could be said as the word "nothingness." In a larger way it could wrap the entire earth.

I live on a small mountain doing farming. I don't have any knowledge, I don't do anything. My way of farming is no cultivation, no fertilizer, no chemicals. Ten years ago my book, One Straw Revolution, was published by Rodale Press in the United States. From that point I couldn't just sleep in the mountains. Seven years ago I took an airplane for the first time in my life and went to California, Boston, New York City. I was surprised because I thought the United States was full of green everywhere, but it looked like death land to me.

Then I talked to the head of the desert department at the United Nations about my natural farming. He asked me if my natural farming could change the desert of Iraq. He told me to develop the way of changing the desert to green. At that point I thought that I was a poor farmer and I had no power and no knowledge, so I told him that I couldn't. But from then I started thinking that my task is working on the desert.

Several years ago, I travelled around Europe. It seemed to me that Europe was very nice and beautiful, with lots of nature preserved. But three feet under the surface I felt desert slowly coming in. I kept wondering why. I realized it was the mistake they made in agriculture. The beginning of the mistake is from growing meat for the king and wine for the church. All around, cow, cow, cow, grape, grape, grape. European and American agriculture started with grazing cows and growing grapes for the king and the church. They changed nature by doing this, especially on the hill slopes. Then soil erosion occurs. Only the 20% of the soil in the valleys remains healthy, and 80% of the land is depleted. Because the land is depleted, they need chemical fertilizers and pesticides. United States, Europe, even in Japan, their agriculture started by tilling the land. Cultivation is also related to civilization, and that is the beginning of the mistake. True natural farming uses no cultivation, no plow. Using tractors and tools destroys the true nature. Trees' biggest enemies are the saw and ax. Soil's biggest enemies are cultivation and plowing. If people don't have those tools, it will be a better life for everything.

Since my farm uses no cultivation, no fertilizer, no chemicals, there are many insects and animals living there within the farm. They use pesticide to kill a certain kind of pest, and that destroys the balance of nature. If we allow it to be completely free, a perfect nature will come back.

Robert: How have you applied your method to the deserts?

Masanobu: Chemical agriculture can't change the desert. Even if they have a tractor and a big irrigation system, they are not able to do it. I came to the realization that to make the desert green requires natural farming. The method is very simple. You just need to sow seeds in the desert. Here is a picture of experimentation in Ethiopia. This area was beautiful 90 years ago, and now it looks like the desert in Colorado. I gave seeds for 100 varieties of plants to people in Ethiopia and Somalia. Children planted seeds, and watered them for three days. Because of high temperature and not having water, the root goes down quickly. Now the large Daikon radishes are growing there. People think there isn't any water in the desert, but even in Somalia and Ethiopia, they have a big river. It is not that they do not have water; the water just stays underneath the earth. They find the water under 6 to 12 feet.

Diane: Do you just use water to germinate the seeds, and then the plants are on their own?

Masanobu: They still need water, like after ten days and after a month, but you should not water too much, so that the root grows deep. People have home gardens in Somalia these days.

The project started with the help of UNESCO with a large amount of money, but there are only a couple of people doing the experiment right now. These young people from Tokyo don't know much about farming. I think it is better to send seeds to people in Somalia and Ethiopia, rather than sending milk and flour, but there isn't any way to send them. People in Ethiopia and Somalia can sow seeds, even children can do that. But the African governments, the United States, Italy, France, they don't send seeds, they only send immediate food and clothing. The African government is discouraging home gardens and small farming. During the last 100 years, garden seed has become scarce.

Diane: Why do these governments do this?

Masanobu: The African governments and the United States government want people to grow coffee, tea, cotton, peanuts, sugar - only five or six varieties to export and make money. Vegetables are just food, they don't bring in any money. They say they will provide corn and grain, so people don't have to grow their own vegetables.

Robert: Do we, in the United States, have the type of seeds that would grow well in these parts of Africa?

Masanobu: As a matter of fact, I saw quite a few plants including vegetables, ornamentals, and grains here in this town (Port Townsend) this morning that would grow in the desert. Something like Daikon radish even grows better over there than in my fields, and also things like amaranth and succulents grow very well.

Robert: So if people in the United States and Japan and Europe wanted to help the people in Africa and reduce the desert, would you suggest that they send seeds?

Masanobu: When I was in Somalia, I thought, if there are ten farmers, one truck, and seeds, then it would be so easy to help the people there. They don't have any greens for half of the year, they don't have any vitamins, and so of course they get sick. They have even forgotten how to eat vegetables. They just eat the leaves and not the edible root portion.

I went to the Olympic National Park yesterday. I was very amazed and I almost cried. There, the soil was alive! The mountain looked like the bed of God. The forest seems alive, something you don't find even in Europe. The redwoods in California and the French meadows are beautiful, but this is the best! People who live around here have water and firewood and trees. This is like a garden of Eden. If people are truly happy, this place is a real Utopia.

The people in the deserts have only a cup and a knife and a pot. Some families don't even have a knife, so they have to throw rocks to cut the wood, and they have to carry that for a mile or more. I was very impressed by seeing this beautiful area, but at the same time my heart aches because of thinking about the people in the desert. The difference is like heaven and hell. I think the world is coming to a very dangerous point. The United States has the power to destroy the world but also to help the world. I wonder if people in this country realize that the United States is helping the people in Somalia but also killing them. Making them grow coffee, sugar and giving them food. The Japanese government is the same way. It gives them clothes, and the Italian government gives them macaroni. The United States is trying to make them bread eaters. The people in Ethiopia cook rice, barley and vegetables. They are happy being small farmers. The United States government is telling them to work, work, like slaves on a big farm, growing coffee. The United States is telling them that they can make money and be happy that way.

A Japanese college professor that went to Somalia and Ethiopia said this is the hell of the world. I said, No, this is the entrance to heaven. Those people have no money, no food, but they are very happy. The reason they are very happy is that they don't have schools or teachers. They are happy carrying water, happy cutting the wood. It is not a hard thing for them to do; they truly enjoy doing that. Between noon and three it is very hot, but other than that, there is a breeze, and there are no flies or mosquitoes.

One thing the people of the United States can do instead of going to outer space is to sow seeds from the space shuttle into the deserts. There are many seed companies related to multinational corporations. They could sow seeds from airplanes.

Diane: If seeds were thrown out like that, would the rains be enough to germinate them?

Masanobu: No, that is not enough, so I would sow coated seeds so they wouldn't dry out or get eaten by animals. There are probably different ways to coat the seeds. You can use soil, but you have to make that stick, or you can use calcium.

My farm has everything: fruit trees, vegetables, acacia. Like my fields, you need to mix everything and sow at the same time. I took about 100 varieties of grafted trees there, two of each, and almost all of them, about 80%, are growing there now. The reason I am saying to use an airplane is because, if you are just testing you use only a small area. But we need to make a large area green quickly. It needs to be done at once! You have to mix vegetables and trees; that's the fastest way for success.

Another reason I am saying you have to use airplanes is that you have to grow them fast, because if there is 3% less green area around the world, the whole earth is going to die. Because of lack of oxygen, people won't feel happy. You feel happy in the spring because of the oxygen from the plants. We breathe out carbon dioxide and breathe in oxygen, and the plants do the opposite. Human beings and plants not only have a relationship in eating, but also share air. Therefore, the lack of oxygen in Somalia is not only a problem there, it is also a problem here. Because of the rapid depletion of the land in those parts of Africa, everyone will feel this happening. It is happening very quickly. There is no time to wait. We have to do something now.

People in Ethiopia are happy with wind and light, fire and water. Why do people need more? Our task is to practice farming the way God does. That could be the way to start saving this world.

Economic Importance

Dryland farming is highly important to ensure the economic stability of a region or nation with arid lands. In the absence of this farming practice, vast tracts of lands in the world would be left barren and unproductive. Even though dryland farming takes a lot of financial investment and hard work to be established, and crop yields are generally comparatively lower, without this form of agriculture the populations residing in the arid areas of the world would have to be completely dependent on external sources of food to meet their dietary needs. This would adversely impact a nation's economy as self-sufficiency, in terms of production of food grains to feed the country's population, would be lost.

Ecological Significance

Today, as the effects of climate change grips the world and the problem of desertification intensifies, more farmers across the world are planning to utilize the methods of dryland farming to cultivate their own crop fields. In the near future, many arable lands of today might have to completely depend upon dryland farming methods to sustain their agricultural outputs.