Tuesday, October 27, 2015

Thirty-five Water Conservation Methods for Agriculture, Farming, and Gardening Part 2.

This is part 2 of this water saving technologies methods for agriculture, farming, and gardening. It lists methods 16 through 35.

16. Organic Farm Soils Require Less Water to Grow Crops

In the Rodale Institute’s 30 year farming systems trial, they found that organic outperforms conventional in years of drought as shown in the photo above. Organic fields increased groundwater recharge and reduced runoff as compared to industrial farming. The organic farm fields had 15 to 20 percent higher water volumes “percolating” through their soils. When rain falls, the organic soils absorb the water instead of running off the surface and taking soil with it. During periods of drought, healthy crop roots can access the stored water present in the organic field soils. And by practicing crop rotation, soil retains more water, reducing erosion and the need for irrigation.
In conservation agriculture or natural farming systems, zero tillage, crop rotations, manure fertilizer, cover crops, and residues help to protect the soil and increase organic matter. During rains, healthy organic soils absorb water and store it better. Good soil structure with macropores allows the water to go deep into the soil where it can be accessed by roots and is less prone to evaporation.
17. Drought Tolerant Livestock Breeds

The Nelore cattle breed is of the Zebu species from India and has been raised extensively in Brazil. It does better than most other cattle breeds in conditions of heat, poor range quality, and drought. Its hallmark is the prominent hump behind its neck. Other breeds of the drought tolerant zebu are found in Africa.
In the U.S., the Texas longhorn is gentle, provides lean meat, and is heat and drought-tolerant.

Sheep are very drought tolerant, requiring as little as two gallons of water per day. During the cooler season they require little or no supplemental water beyond their forage intake. Navajo-Churro Sheep are a drought-resistant breed which is tolerant of temperature extremes and can subsist on marginal forage with minimal grain. The Dorper sheep (see photo above) is a hardy, popular breed in South Africa. Originating in arid conditions, it is highly adaptable to many environments. Dorper’s have been popular in the U.S. since 1995.

Free range chickens are also efficient meat producers requiring little, but adequate water.
18. Change our Diets

To conserve water, diets should be regionally appropriate and in season. Water use is embedded in our food processing, packaging, and distribution systems, so eating locally, unprocessed food saves both water and energy. Some argue that meat consumption is an extravagant use of water, but if a region has abundant grass and rainfall, like for example New York state or Vermont, then grass fed livestock is a water efficient protein source from either meat or milk.

Drought tolerant crops should be consumed in drier regions, such as dried beans, lentils, wheat, millet, and squash. Rainfed or drip irrigated fruit and nut trees produce water efficient food. Some tuber crops and root vegetables are also water efficient.

Much of today’s food transportation system is extremely efficient, allowing for easy trade from the regions that are best suited for growing certain crops. But we need to pay attention to where food comes from when buying at the market, casting an important vote with each dollar spent.

We can save water by taking care to reduce food waste on a personal level. Don’t buy more than you need, store it appropriately, and compost the waste to recycle it into future food.

Thankfully, there is an enormous amount of resilience and adaptability in the human diet.

19. No Biofuels Mandates, Please

Biofuel production competes with food production. In the energy-water-food nexus, the IEA (International Energy Agency) predicts that biofuels production will attribute 30 percent of the new demand for water by 2035. It would create the second largest new demand for water, next to coal. (Fracking requires less water than biofuels production.)

The IEA anticipates a 242 percent increase in water consumption for biofuels by 2035. Ethanol and biodiesel now account for more than half of the water consumed for primary fuel production while they only provide less than 3 percent of the energy used to fuel our transportation fleet.
The IEA estimates that corn ethanol uses 4 to 560 gallons of water for every gallon of corn ethanol produced, varying by region. This compares to gasoline which uses .25 to 4 gallons of water per gallon of fuel produced. Furthermore, precious aquifer water should not be permitted to provide irrigation for corn grown for fuel. According to one study, consumptive water use for ethanol production in the U.S. increased 246 percent between 2005 and 2008 and has particularly gone up in the Ogallala Aquifer region. The GAO estimates the average water consumed in corn ethanol production at 324 gallons of water per gallon of ethanol, 88 percent from groundwater.
20. Recycle Wastewater

Wastewater can be recycled and reused for agriculture. Urban wastewater that is treated adequately can be recycled into rivers where it can be reused downstream.

Nations which reclaim the highest percentage of their wastewater include Israel, Spain, Australia, Japan, Middle Eastern nations, Mexico, Latin America, Caribbean, and the U.S. states of Florida and California. Reclaimed water is used for agriculture and irrigation.

Costs for large scale treatment of wastewater are much higher than having available freshwater, even for crops which are not directly consumed by humans. For urban wastewater reuse, the agricultural production needs to be reasonably close to the city providing the water source.
Untreated wastewater is the only option for irrigation in many poor farming regions. Affordable treatment technologies need to become more available to these areas which maximize benefits with the lowest possible risks. Unique and regionally appropriate solutions should be used.

Domestic graywater (laundry, dishwashing and bathing water) can be collected and recycled through a setup of wetlands and aquatic plants which purify it so that it can be used in the garden.
21. Qanats

Qanats are old Persian water management systems which draw upon underground water sources, often at the base of mountains. They allow for the creation of a living oasis in the midst of deserts. They are made up of a series of well-like vertical shafts, connected by gently sloping tunnels. Large amounts of water are brought to the surface without pumping by using gravity. Qanats as a water source are nearly as reliable in dry years as in wet years. Qanats allow water to be transported over long distances in hot dry climates with minimal loss of water to evaporation. They are used to provide irrigation in hot, arid and semi-arid climates and many are still in existence today, operating in regions from China across to Morocco.
22. Rain Water Harvesting and Rain Gardens

The city of Santa Rosa, California offers a rebate for each gallon of rainwater stored.
The city of Raleigh, North Carolina worked together with its fire department to set up a rainwater collection and storage system that helps the fire department use less of the city’s drinking water supply.
Some gardeners set up rainwater collection systems which are used to water their vegetable gardens, often employing them in drip irrigation plans.
In addition to harvesting rainwater from roofs, there are methods to harvest rainwater in the soil. The goal is to prevent runoff by encouraging water infiltration into the soil, and then minimizing evaporation. One way to do this is by planting a “rain garden,” which is a collection of shrubs or native plants located in a depressed spot that collects runoff. These collect up to a third more water from roofs, sidewalks, driveways, and lawns that would otherwise enter waterways. Urban rain gardens filter out pollutants to help keep local streams cleaner.

Rainwater may be harvested on a small scale to grow fruit trees, water small livestock, or support fish ponds. The collected water can be stored in small tanks above or below ground, in drums, or in small reservoirs.

On a farm, in situ rain harvesting and filtering are accomplished through having buffer strips, grassy areas, terraces, off-stream storage reservoirs, and natural wetland areas.
23. Canal or Ditch Irrigation

Canal irrigation is a surface flooding irrigation method, the most common type of irrigation in the world. Because surface flooding accounts for most irrigation, it is very important to develop and promote methods or technologies which improve the efficiency of canal irrigation.
This is a method of transferring water from a water source to fields. Canals, ditches, basins, furrows, borders, pipes, and surface flooding provide ways to move the water by gravity. Surface flooding can lose more than 50 percent of the water used through evaporation and runoff. Furthermore, soil salinity, loss of nutrients, and runoff pollution can occur. Laser leveling of the land helps improve efficiency.

Seepage from canals or ditches can be reduced by reinforcement of the canal banks and by sealing or lining the canals. Roughly 60 to 80 percent of the water that is lost in unlined canals can be saved through hard-surface lining. Lined canals and ditches may use concrete, concrete blocks, bricks or stone masonry, sand cement, compacted clay, or membranes made of plastic or other materials to line the bottom and sides.
Canal maintenance should be a priority. Inspections are helpful, and keeping the systems weed-free greatly improves their efficiency.
(Note that the top photo, taken here in Colorado, shows a concrete lined ditch with siphon pipes to be placed in furrows for irrigation. The lower photo, also taken here in Colorado, shows a ditch lined with black plastic.)

24. Polyethylene or Aluminum Gated Pipe Irrigation

Gated Pipes made from aluminum or plastic can be used in the arid West instead of ditch irrigation and they can also be used on laser leveled land. Gated pipes reduce evaporation and leakage, saving 30 to 45 percent of water used, while reducing erosion. The gates can be opened and closed, allowing for watering only the areas, or furrows selected.
The system is set up by delivering water into the pipe using a concrete box containing a tight screen or filter which keeps debris out of the water entering the pipe. Pipes may range from four inches to 15 inches in diameter. Every two feet, the pipe has a plastic slide, or “gate” that can be opened or closed using an irrigating “shovel”.
This is a form of flood irrigation, or gravity irrigation. It is popular in the U.S. and Latin America for growing corn, soybeans, fruits, nuts, vegetables, sugar cane, and pasture land. The cost and operating expenses are comparatively low for this system of irrigation.
25. Half Moons, Bunds, and Terraces

Some methods within this category can conserve both water and soil while requiring little capital investment. Terracing, contour bunds, infiltration pits, tillage, integration of tree crops, and green manuring all help to increase water inflitration and storage in the soil.

Bunds: On land with slight or moderate slopes and light to medium weight soils, bunds can be constructed to reduce rainwater runoff, gully formation, and soil loss. Bunds are raised earthen barriers which must be constructed by machine or by hand. They require a significant amount of labor and take a small amount of land out of production. They help rainwater to percolate into the soil. Bunds are used in terraced rice farming to retain water in the paddies.

Half Moons: By constructing half moon structures on slight slopes, rainwater is collected and erosion is stopped. Like bunds, they are appropriate for lighter soils that form surface crusts. They help enable the production of drought resistant crops like millet, where there is little rainfall. Half moons can be used for forage crops in rangeland degraded areas, too.
Terraces: These serve as small dams on sloped farmland and prevent gully washing. While expensive to construct they help preserve soil and water quality and grassy buffer strips provide nesting habitat for wildlife.

26. Pumps for Irrigating

It wasn’t until motorized pumps powered by fossil fuels were used to irrigate from underground water sources, that aquifers and groundwater sources could be pumped beyond natural replenishment rates. This has led to unsustainable drops in aquifer levels in India, China, and the U.S.
But, there are simple, nonmotorized methods to pump water from underground sustainably that are immensely valuable to small farmers in undeveloped regions of the world.
Treadle pumps: Bamboo (or metal) treadle water pumps have enabled poor farmers in places like Bangladesh

to access groundwater during the dry season. Treadle pumps draw groundwater to the surface using a manually powered suction system. They can be made locally and there have been programs to supply them in certain areas. Today, there are more than two million of these that have been distributed world wide. They can be used to fill containers used for micro-irrigation or bucket drip irrigation systems. These are viewed as a stepping stone between hand lifting water and obtaining motorized pumps.
Hip Pumps: According to KickStart, this $30 pump which began selling in 2008 can irrigate an acre or more. It can pull water from 7 meters and push water an additional 14 meters above the pump.

These micro-irrigation pumps are available in Africa, Asia, and Latin America.
Solar Pumps: Solar and wind energy can be used to power pumps for irrigation as can small biomass plants, and micro-hydroelectric plants.
Motorized Pumps: China has been exporting around four million pumps annually, after decreasing the weight and the cost of small irrigation pumps. Now, more than 60 percent of India’s irrigation is being done by smallholder farmers pumping groundwater. 
27. Collecting Fog or Mist

Some call it harvesting water from thin air. This ancient practice, evident in archaeology of Israel and Egypt is being revived again today. By using nets strung across mountain passes, or stretched on poles located in foggy areas, gravity collects clean potable water for local residents. Water droplets attach to the netting and run down into gutters beneath the nets. The collected water may be further collected into tubes, taking it to a lower village or point of water storage. One square meter of netting can provide five liters of water per day.

The plastic netting is a coarse woven mesh, used to shade fruit trees. It is inexpensive and readily available. Various collection methods can be constructed, to fit the specific setting.
In addition to gaining potable water for drinking, collecting water from fog can be used for agriculture and starting trees for reforestation, too. Nets have been used to provide direct irrigation to quinoa in South America.

The areas with the best climatic and geographic conditions for collecting seasonal fog include some mountainous areas, the Atlantic coast of southern Africa and South Africa, Oman, Sri Lanka, China, Nepal, Mexico, Kenya, Morocco, Yemen, Guatemala, Chile, Peru, and Ecuador. In Chile, this method has been used for over 30 years. 

28. Deficit Irrigation

In deficit irrigation, the goal is to obtain maximum crop water productivity rather than maximum yield. By irrigating less than a crop’s optimal full requirement, you might reduce the yield by 10%, but save 50% of the water. With supplemental irrigation to rainfed crops in dry lands, a little irrigation is selectively applied during rainfall shortages and during the drought-sensitive growth stages of a crop. (These important stages are the vegetative stages and the late ripening period.)
The end goal is to maximize irrigation water productivity, even if it means some loss of production. As a success story example, results from using deficit irrigation have been quite dramatic for wheat production in Turkey.

29. Mycorrhiza Fungus in Soil Can Reduce Plant Water Needs by 25 Percent

Mycorrhiza, which means “root-fungus” grows in healthy soils and functions symbiotically with plants by enhancing the uptake of phosphorus and other nutrients. The fungus attaches to plant roots, increasing the root surface area which comes in contact with the soil. It excretes enzymes which allow it to dissolve soil nutrients, and extends the life of the root.

This fungus increases the drought tolerance of plants and can reduce water needs by 25 percent. It increases the fruit and flowering of plants while reducing the need for water and fertilizer. It also enables plants to grow in salty or contaminated soils and increases the temperature stress tolerance for plants. It helps protect plants from disease, and helps store carbon in the soil. Mycorrhiza has the potential to bring poor and degraded lands back into cultivation.

It is possible to encourage mycorrhiza growth in soils by adding compost to your garden soil, by not using synthetic chemicals, using minimum tillage, rotating crops, and growing cover crops. By cold composting, or mulching your garden with shredded leaves each fall, you can promote optimal Mycorrhizal fungi growth. Or, it can be purchased and added directly to sterile potting soils, or degraded soil.

30. Using Less Water to Grow Rice

Paddy rice consumes far more water than any other cereal crop, although much of this water is recyled. It also is the staple grain for half the people of the world. Three-fourths of the rice produced comes from irrigated fields, and irrigated rice uses up to 39 percent of global water withdrawals for irrigation. It takes about 2,500 litres of water to produce 1kg of rice.

Traditional rice varieties tend to have lower yields and longer crop cycles but they require less fertilizer, use less expensive seeds, and are preferred by consumers, bringing a higher price. Because of higher input costs and lower market values for high-yield rice varieties, farmers often opt to plant traditional rice varieties instead.

Ecologists have labeled five categories of rice plants according to water needs as being rainfed lowland, deep water, tidal wetland, rainfed upland and irrigated rice. Researchers have been investigating improved ways of growing rice with less inputs and/or water.
Below, are some ways found to reduce water use in rice growing.
  • System of Rice Intensification (SRI) (See #5 in this series.)
  • Alternate Wetting and Drying [AWD] lets fields fall dry for a number of days before re-irrigating them, which can maintain yields with 15 to 30 percent of water savings. In Bangladesh, the AWD technique reduced water consumption by 30 to 50 percent.
  • Aerobic Rice is grown in water-scarce regions, without ponded water and saturated soil. It uses 50 percent less water, and produces 20-30 percent less yield. These are high-yielding varieties that grow under non-flooded conditions in non-puddled, unsaturated (aerobic) soil. They rely on irrigation water, greater fertilizer application, and greater use of pesticides. The shorter growth cycle of these varieties enables farmers to grow other crops (rice or other plants) after the rice crop is harvested.
  • New varieties like short-season rice significantly reduce water use. Rice produced 40 to 45 years ago required 160 days from seed to harvest, compared to 135 days for short-season varieties which has reduced the amount of water needed by about 20 percent over the last 30 years.
  • Pioneered by China, hybrid rice – a cross-bred robust variety – has increased land and yield productivity while reducing water use. It is taking China about 1,750 liters of water to produce 1 kilogram of rice as compared to 3,500 liters in India.
  • Genetic modification might be able to improve water efficiency of rice by another 30 to 40 percent.
  • Good land management, using laser leveling of compact soil fields with channels and dikes helps save water in California.
  • In Australia, rice grown with saturated soil culture used 32 percent less irrigation water than conventional methods in wet and dry seasons.
  • ACIAR is supporting trials of permanent raised beds in mixed cropping systems (rice–wheat and other combinations) in India, Pakistan and China.
  • About 13 percent of global rice area is dryland rice. Yields are quite low and it is mostly grown for subsistence. In Southeast Asia, most dryland rice is grown on rolling or mountainous land. Some newer rainfed rice varieties can achieve yields close to those of irrigated fields, however.
  • A newer variety of flood tolerant rice has also been shown to withstand drought better. About 8 percent of the world’s rice is classified as flood prone.
Some of the above methods also reduce methane emissions from rice growing, significantly.
Finally, to achieve more ‘crop per drop,’ wheat and crops that do not grow in flooded areas have the potential to produce food with less water. A rice field takes 2 to 3 times more water than a wheat or corn field. So, it is possible that in the future wheat might supply a growing share of the world’s staple grain.
31. Soil Moisture Sensors

Incorporating soil moisture sensors into an irrigation system is an important tool for water conservation. It not only prevents over-watering, but saves unnecessary pumping costs and helps prevent leaching of fertilizers.

By monitoring soil moisture conditions, yield increases can be dramatic through careful water applications during the most critical plant growth stages.

By watering less, plant roots grow deeper and there is less disease.

Moisture sensors can be used for commodity crop farming, vegetable farming, or orchards.

The probes are made up of multiple soil moisture sensors. They range in price, with the higher priced models generally more accurate.

Some center pivot irrigation systems combine soil moisture sensors with a computer that controls the operation of the pivot.

The University of Nebraska now provides a Crop Water App for the iPhone and iPad based on Watermark sensors from IRROMETER® which are installed at depths of 1, 2 and 3 feet.

32. Good Drainage

Too much water is as great a problem as too little. Good drainage is important in water management because poor drainage leads to soil degradation and salinity which can greatly diminish the yield and quality of most crops. Drainage factors include soil type, compaction, and topography.

Soil compaction reduces the amount of pore space in soils and results in soil that will not drain quickly. This affects plant growth because plant roots require air. Most plants cannot survive for too long under water or in damp soils. Poor drainage causes diseases and root rot. It not only affects the returns to the producer but also can result in increased runoff during heavy rainfall events, therefore increasing water erosion.

When trying to improve damaged land that is saline or waterlogged, moving soil, installing drainage pipes, and mulching can help. Other methods of improving drainage include good crop rotation practices, adding manure and compost to improve macropores in the soil, and reduced tillage.

Chinampas: (above photo) This farming system is thousands of years old from the Aztecs of Mexico’s lake country. Chinampas are long narrow patches of ground, called “floating gardens”, bordered by canals on each side. Approximately 98 feet by 8 feet (30 meters by 2.5 meters), they are man-made by building up earth during canal excavation through stacking alternate layers of canal muck and rotting vegetation.
33. Agroforestry

Agroforestry, or using trees as part of the agricultural landscape, can improve water and soil quality and reduce evaporation rates. These biodiverse systems have reduced nutrient and soil runoff, or erosion. The trees drop leaves and twigs which improve soil quality so that rainwater infiltrates better. Many crops are shade tolerant. The trees can be trimmed to allow more sun to reach the garden spaces and for use for firewood.

One system of agroforestry mixes livestock with trees and forage. The animals benefit from shade and the trees can provide nuts or timber or fruit.

Intercropping with trees can produce honey, fruits, nuts, maple syrup, medicinal plants such as ginseng, and mushrooms.

As field windbreaks, trees help to control wind erosion, provide wildlife habitat, control soil erosion, and protect livestock.

Although not meant to produce a large amount of a single crop, these systems can provide good yields with a variety of outputs. By mixing trees, shrubs and seasonal crops there is more resilience to insects, diseases, drought, and wind damage.

34. Reduce Food Waste

Food wasted is water wasted and so much more. More than 30 percent of the food produced is lost or wasted. Food waste can be lessened through improvements in every step of the supply chain – storage, transportation, food processing, wholesale, and retail. The consumer must learn to purchase and eat wisely, so as not to waste.

When processed food gets thrown away, all of the water, energy, and labor used to process, transport, refrigerate, and distribute that food was wasted. When fresh produce or meat is thrown away, everything that went into the production and cooking of those foods was wasted.

Some waste in a food system is normal, and it can be put to good use as compost to create rich soils for growing next year’s food. It would be great if all food that is not consumed could be recycled into compost. The “huge” problem of obesity results in the squandering of both food and health.

In the developing world, small, local storage silos can greatly reduce rot, waste, and rodent damage to crops. Refrigeration, improved communication, and distribution infrastructure advancements will also help.

35. Water Conservation Also Means Keeping Our Water Clean and Uncontaminated

What good would it do to conserve water if the water that remains is contaminated?

We must embrace smart practices and have government regulations in place that protect our water from becoming contaminated. Agriculture is guilty of water contamination from unsustainable land overuse practices that result in the runoff of fertilizers, manure, pesticides, soil, and herbicides.
Industrial agriculture runoff has contributed to the Dead Zones in various coastal locations around the world. Here in the U.S., our Dead Zone is located in the Gulf of Mexico and is a hypoxic water area the size of New Jersey. It results from agricultural and municipal waste runoff that funnels into the Mississippi River.

Overuse of nitrogen fertilizer has contaminated large amounts of ground water in regions such as Minnesota, where industrial agriculture is practiced. This has resulted in the loss of safe drinking water from underground wells for the families who live in these areas.

Poor farming practices that lead to soil erosion and harmful chemical runoffs not only degrade the land, but contaminate streams, lakes, and rivers. By nurturing wetlands, keeping waterways natural with buffered areas, incorporating grassy and woody buffer strips into farmed land, and building terraces or contours on slopes, farmers can help to keep their local water clean. By using methods which keep soil healthy — including organic farming, minimum tillage, rotational grazing, and crop rotations — soil absorbs and keeps water pure.

END PART 2. To see PART 1, click HERE.

Readers, note that this originally appeared on my former site, Big Picture Agriculture, February 2013.

Copyright Notice: Please do not republish from this post in part or in full without permission.