Sustainable water management in the forest garden

The extreme heat and drought that we have had here in Stjärnsund region has done it once again clear to me how important it is to work with one of the most important basic principles of creating a forest garden - Sustainable water management.

In over a month, between the beginning of June and first week of August, we have just received 15 mm rainfall total in Putt Myra forest garden and the temperatures have been closer 30 degrees on the day of more weeks. At the same time requires a hundred newly planted shrubs and trees watering every other day in order to survive. I have previously written about swales and their function to distribute the water in forest garden, but what are the other options to make water management more sustainable?

A mikroswale stuffed after the last big rain storm at the beginning of July,.
A mikroswale stuffed after the last big rain storm in early July.

The thing that has saved our trees and shrubs so far, especially our ponds. Two of the ponds dug already 2012, and those rescued from the forest garden to wither during last year's long summer drought. Last spring, we dug two ponds (watch movie clip nedan) to protect ourselves better from väderextremen which seems to be increasingly common. One of the ponds is paired with a swale and the watering of the plants along with Swalen occurs automatically when the dam overflows when strong rains.

Otherwise we are watering so far mostly by hand with watering cans. We do this because we do not want to invest in a complicated pump- and irrigation systems, but also to hand watering provides a personal contact with each plant and the opportunity at each watering to see how every plant feel.

The newly dug pond filled rapidly and has been an invaluable resource during the long summer drought.
The newly dug pond filled rapidly and has been an invaluable resource during the long summer drought.

While watering is a right way to actively manage the plants' water needs, there are more, more passive way to achieve sustainable water management. Keeping the ground covered is a technique mentioned in several previous posts. Benefits of mulching is to reduce evaporation from the soil, temperature variations are reduced and there is less risk that the Earth gets a hard crust that is closest to the water and can cause erosion problems especially on clay soils. Furthermore creates mulch the conditions necessary for life on earth to develop in the best way. But what mortal life with sustainable water management to make?

Keeping the ground covered with organic matter increases the soil's capacity to hold water.
Keeping the ground covered with organic matter increases the soil's capacity to hold water.

The answer is that a soil water storage capacity increases the higher the organic matter content is. The relationship is illustrated in the figure below. Field capacity is the maximum proportion of the water that is available to be taken up by plants. Facing the water content below wilting point, plants can not meet its water needs anymore and begins to wilt. As shown in the figure, increasing field capacity much faster than the wilting point for each percentage of organic matter in the soil increases.

Earth's ability to hold plant-available water increases the higher content of organic matter in the soil is (Modified from Bradley & Because, The Nature and Properties of Soil, 2007)
Earth's ability to hold plant-available water increases the higher content of organic matter in the soil is (Modified from Bradley & Because, The Nature and Properties of Soil, 2007)

To work actively to provide organic matter to the soil, make use of dynamic accumulators and other plants that improve soil fertility and to keep the ground covered has thus also of great benefit to help plants meet their water needs. Failure to create a living soil rich in humus and can thus reduce their labor in the form of watering, and get one step closer to the goal of creating a maximal self-tailing cropping.

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