Climate change is impacting the agricultural sector in many ways, one of the most critical being the increasing scarcity of water. With more areas becoming too dry for irrigation, farmers are looking into older methods associated with conservation agriculture, such as dryland farming, dramatically reducing the need for irrigated water, now making a resurgence. Evolved to adapt to arid conditions, dryland farming is already widely practised in Australia – the world’s driest continent.
What Is Dryland Farming?
Dryland farming signifies the production of crops without irrigation in regions with a low average or highly variable rainfall. The method is characterised by soil’s water evaporation potential meaning that the soil’s potential yearly evaporation exceeds annual precipitation. Associated with a cool rainy season, followed by a warm dry season, the main idea behind dryland agriculture is to use the moisture stored in the soil from the previous wet season to produce crops during the dry period. Soil tillage is used to bring up water, and the ground is compacted to seal in the moisture.
What Is the Difference Between Dryland and Wetland Farming?
Unlike dryland farming, wetland farming depends heavily upon rains and irrigation. It is used in regions of high precipitation zones where water supply is available throughout the year, and the rainfall is higher than the soil moisture requirement of crops during the wet season. Farmers use irrigation ditches where the water is led from bodies of water such as ponds, streams or rivers to the paddocks via a pump and a series of hoses or pipes. The wet conditions support the growing of crops like sugarcane and rice that are tolerant against waterlogging, compared to drought-resistant cultures used in dryland farming.
What Crops Are Good for Dryland Farming?
Cultivated without supplemental irrigation during the dry season, crops grown in dryland farming need to be quick maturing and, as mentioned above, suited for arid to drought conditions. They also have to preserve as much moisture in the soil as possible. For example, dwarf varieties have less leaf area and therefore lose less water. To reduce water loss, some plants, like corn, curl their leaves during the day and open them at night.
In Australian dryland systems, crops are usually grown on a broad hectare scale. They include maise, cereals, legumes, oilseeds and fodder. In fact, dryland products include most of the grain production in Australia. Although many fruits and veggies are known for needing a lot of water to grow, melons, potatoes, squash, tomatoes, grapes, garlic, peppers, aubergines and pumpkins, for example, can also be produced using dryland farming methods. It is more challenging to grow shallow root systems such as lettuce and other small greens on a dry farm, but not unthinkable with the right timing.
What Are Dryland Farming Methods?
In dryland farming, where the yield is contingent on the cumulative effects of water deficits on plant performance, the timing is crucial. Planting crops at the wrong time could make them weak and susceptible to disease. It is also critical to understand the processes of water supply as dryland farming depends on making the best use of stored soil moisture. Minimising water loss and soil erosion, managing pests, soil fertility, and organic matter help achieve the highest results. There are several methods that the farmers can apply to accomplish that:
- The reduced number and wider spacing of plants plus strict weed control ensure fewer plants compete for soil moisture.
- Mulch around plants helps retain moisture, keeps roots cool and repels weeds.
- Post-harvest tillage creates dirt mulches and stubble, destroys weeds before the dry season, and blocks water flow down the slope.
- Tillage and plantings across or perpendicular to the slope of the land also block the downward movement of water.
- Light cultivation of the ground after every rain pour prevents crusting.
- Deep soil (10 feet – 3 meters) with no clay, sand, or gravel seams interferes with the capillary movement of water.
- Shelterbelts of trees or shrubs reduce wind speeds and cast shadows, reducing evaporation by itself and reducing wind erosion.
Is Dryland Farming Sustainable?
Global climatic change, growing population and rise in consumption make it necessary to provide more food in a sustainable manner. Dryland farming, prioritising water conservation, sustainable crop yields, limited fertiliser use and wind and water erosion constraints help to preserve water and encourage a more viable relationship with the land.
However, changes in rainfall patterns – in many areas low and insufficient – pose a significant challenge to profitable farming in dry regions. Farmers must avoid temporary intensive exploitation and subsequent abandonment of the plots. Instead, they should look to restoration technologies, such as planting soil-improving trees or shrubs, that can, without synthetic fertilisers and irrigation, recover nutrients and moisture and produce a protective layer of mineral-rich leaf litter. In addition to increased productivity, better soil quality also helps sequester carbon dioxide back into biomass and soil, reducing the environmental impact of farming practices and making dryland agriculture a valuable aspect of more sustainable and resilient food production.
How to Get the Most Out of Dryland Farming?
Although the main components of dryland farming have been around for centuries, management practices have experienced a continuous evolution. Introduction of plant growth-promoting rhizobacteria (PGPR) and water-saving superabsorbent polymer (SAP) have contributed to yield gains. PGPR promote plant growth by protecting plants against pathogens, providing improved mineral nutrition and producing plant hormones or other molecules that enhance growth. SAP’s help to reduce irrigation needs for crops by storing nutrients and water to release them in drought conditions.
For the crucial task of weather monitoring, luckily, farmers these days don’t have to rely on looking for signs in nature—they can access the information on apps instead.
Weather Zone, named Australia’s favourite weather app, provides real-time local weather, accurate meteorological data, and custom features, including a synoptic map of Australia with rain areas and amounts.
SoilWaterApp gives a ready estimate of plant-available water in the soil during crop and fallow phases. It estimates soil water based on proven water balance, weather and rainfall data, soil description, soil and crop cover conditions on paddocks for likely outcomes
eAgronom, in cooperation with IT company SuperHands have recently introduced soil sensors to their features. Soil sensors measure soil temperature and moisture, air sensors air temperature and humidity helping farmers time tasks – when to sow, fertilise, or spray. They also help predict yield by assessing soil temperature and moisture fluctuations during the vegetation period, reducing costs and saving time.