Dry farming: how to grow produce without water

What is dry farming? It is the set of techniques practised since ancient times in arid areas such as those in the Mediterranean, to cultivate produce without irrigation and with minimal rainfall. In a broader sense, dry farming refers to techniques that are focused on more efficient water use, with the aim of saving water even where it is not scarce. These are all techniques you can adopt in the garden and countryside, to consume less water and avoid wasting it.

In actual fact, saving water is more necessary than ever. Recent years have seen rising temperatures and decreasing rainfall, with frequently intense cloudbursts that nevertheless provide scant useful rainfall, which is the portion of total rainfall that is absorbed by the soil and therefore available for plant uptake. For both professional and amateur growers, this means irrigating more and for longer. Although it's not possible to grow produce without any water, today we'll see how to grow with limited water and also how to save it.

Dry farming in practice: the techniques

Dry farming strategies you can adopt even in your garden or in the countryside include: storing natural water resources (rain) in the soil as much as possible, reducing water loss from the soil, planting drought-resistant species and varieties, and adopting cultivation techniques that conserve water.

Let's start with the last of these. The aim behind dry farming techniques is to maximise water conservation in the soil and thereby minimise the need for irrigation. Here's what you can do in your garden or vegetable patch to optimise water use:

• Soil tillage

• Weed control

• Protection from wind

• Mulching

Shallow soil tillage involves incorporating fertiliser and/or organic matter such as manure or compost into the topsoil. It is typically done when breaking up clods of earth with a rotary tiller or two-wheeled tractor to prepare the vegetable patch or flower bed before introducing plants. In addition to making the soil less compact and more hospitable for roots, organic matter increases its water holding capacity.

Especially in clay soils, tillage breaks up the surface crust of the soil, whilst also making the earth more porous and therefore more permeable, thus facilitating water infiltration. At the same time, it reduces runoff on the soil surface, which is a major factor contributing to water loss. Furthermore, soil that is more porous and softer is generally a more favourable substrate for plant growth. On this topic we recommend reading our article on how to till soil, particularly clay soil.

Surface treatments reduce evaporation, another major cause of soil moisture depletion, by disrupting the capillary rise of water from deeper soil layers to the surface. Furthermore, by eliminating weeds they limit transpiration, which is water loss through leaves. Eliminating weeds also benefits cultivated plants, as weeds aggressively compete not only for water, but also for nutrients, light and space. Hoeing is a shallow tillage process that involves loosening the soil with a hoe or similar tools while crops are actively growing. This process helps to reduce moisture evaporation, aerate the soil and control weeds.

Particularly in the countryside, deeper tillage such as ploughing helps plant roots to grow deeper and access more moisture in the soil, including water tables that are rising closer to the surface.

The amount of water evaporating from the soil and transpiring from leaves— collectively referred to as evapotranspiration—depends on air temperature, humidity and wind speed. To reduce the effect of the wind you can use windbreak barriers in the form of dense nets or lattices supported by frameworks. As a windbreak against prevailing winds in your area, you can also use rows of plants, hedges or individual trees. Windbreaks also have a shading function, protecting your plants from excessive direct sunlight.

A very effective system to protect the soil from solar radiation and conserve soil moisture by reducing evaporation is mulching. Mulching involves covering the soil with natural materials – such as a thick layer of straw, grass or dry leaves – or other materials (plastic or biodegradable sheeting). The effectiveness of mulching against evaporation is highest during the early stages of plant growth, when the foliage is less developed and transpiration rates are accordingly minimal. Mulching doesn’t just benefit your vegetable patch and flower beds; you can also use it to protect shrubs and trees in their early years, including fruit trees and vines in the countryside. This technique helps to preserve the soil structure and keep weeds under control. In the garden, it also isolates vegetables and fruit from the ground, keeping them healthier and cleaner. What’s more, mulch made with natural materials nourishes the soil. Here you will find our suggestions for effective mulching.

In the countryside, if you have an orchard or vineyard, planting grass cover keeps the soil porous and permeable while also enriching it with organic matter and preventing runoff. However, it doesn't lead to water savings, since the grass competes for moisture with your crops. However, mowing grass cover, such as with a brushcutter, flail mower or garden tractor, helps to minimise water loss through transpiration from the grassed areas.

Dry-farming plants

To grow crops with no water, or rather, with less irrigation and more use of natural water resources, you essentially have two options. You can choose dry-farming plants, which need less water, or plants with a growing cycle that benefits most from seasonal rainfall and that are harvested before the warmer, drier months arrive.

The first type of plants typically have deep, spreading roots that can access water from various soil depths, and/or have other characteristics that make them drought resistant. The second type can be autumn-spring cycle plants, which are sown in autumn and harvested in spring. Alternatively, they can be spring-summer crops, which you can start sowing/transplanting as early as possible, for example by selecting early varieties, or by using a seedbed to germinate seedlings indoors. Other suitable spring-summer crops include fast-growing vegetables such as chard, some lettuce varieties, radishes, rocket and spinach.

Vegetable plants with modest water requirements also include legumes (especially chickpeas, but also beans, peas and others), alliums (garlic, onion, shallot) and potatoes. Generally speaking, dwarf and determinate varieties (i.e. which grow to a smaller height) need less water than other varieties of a given species. Added to this are individual varieties – ancient, uncommon, locally selected, etc. – with low water requirements.

By contrast, in the countryside you can plant vines and olive trees, which are very suitable for arid environments due to their deep and extensive root systems. Other drought-resistant fruit trees include fig, jujube and almond trees. The rootstock also plays a significant role in determining the drought resistance of a tree species.

Growing produce with limited water

As we have seen, dry farming emphasises careful soil management to maximise water retention and minimise water loss. It's not so much a system for cultivating without water, but rather, it relies on rainwater as the main water source and supplements it with minimal irrigation when necessary.

Whether in the vegetable patch or in the countryside, you need to adopt an efficient irrigation system such as drip micro-irrigation, which delivers water directly to plant roots in small, localised amounts, without wetting the entire surface of the soil. Avoid sprinkler irrigation, especially because it causes water loss through evaporation from the soil and leaves, doesn't provide uniform coverage and can encourage weed growth. Furthermore, wet leaves are particularly vulnerable to fungal diseases.

In addition, to avoid wasting this precious resource, you can create a system to harvest rainwater from the roof of your house and/or garage and store it in a tank. You can also irrigate with water used in the kitchen for washing fruits and vegetables.

To save water and minimise unnecessary irrigation, dry farming is useful not only in arid areas, but also where water access is challenging and you need to resort to a water pump, for example. By the way, here are some ways in which water pumps are handy for irrigation.

A garden that conserves water and minimises waste is more sustainable: find out here what a sustainable garden consists of.