Planting Season? In the Desert?

Sunday, January 24, 2021 11:00 AM

Planting season is in full swing in Israel's south, a sparsely populated expanse of arid and semi-arid regions with very little rainfall. How does KKL-JNF do it? Pablo Chercasky, the director of KKL-JNF's Gilat tree and plant nursery, explains.

Pablo Chercasky, director of Gilat nursery. (Photo: KKL-JNF Photo Archive)
Planting season in Israel's semi-arid south began at the end of this past October (2020), just after the first rains. At the KKL-JNF Gilat Plant Nursery, KKL-JNF forest worker Jibril Abu Kaiyan was busily loading trays of seedlings onto a flatbed truck.

“We need at least 20 centimeters of humidity [depth] in the soil to start planting,” explained Pablo Chercasky, director of the nursery. “This year the rains started pretty late in the season. There have been some years that we've had good rainfall already in September, but this year it's late, and some people say that it will be a dry year.”
Loading trays of seedlings onto a flatbed truck. (Photo: KKL-JNF Photo Archive)

The planting will continue until all the saplings planned for this year have been planted -which can end sometime in December or continue until spring, depending on whether or not saplings need to be replanted due to the first ones having been stolen, Chercasky explained.

With the use of cutting-edge technology, the nursery produces about half a million seedlings each year. With careful monitoring, the seedlings grow into the shrubs, trees, vines and cover plants that are planted in forests and public gardens, on army bases, and around southern communities, in order to restore desertified land and improve quality of life.

Chercasky with saplings inside the propagation greenhouse. (Photo: KKL-JNF Photo Archive)
A specially developed computerized system tracks the entire seedling production process, from its beginning as a seed or cutting up until its development into a mature seedling. The production process includes pruning, pesticide application and transplantation and is all documented.

The production process for the saplings begins in the germination chamber, where the incubated seeds are sprouted, before being moved to the propagation greenhouse where they are irrigated and exposed to sunlight. Once they reach a healthy size, they are ready for transplant. The growth period differs for each species - for example, Acacia seedlings -one of the native trees planted in the regions’ forests - reach transplantation stage within a week, while palm species can take up to a month and a half to be ready for transplantation. The higher the temperature, the faster the seedlings grow. They complete their time at the nursery in the Plant Seedling Cultivation Plots until they are ready for transportation and planting.

The whole process takes about on average from 6 to 8 months, depending on the species of tree.

In addition to the Acacia and palm seedlings, the nursery cultivates a variety of trees from seed to sapling, including Carob, Tamarisk, Eucalyptus, Fig, Mulberry and Christ's thorn jujube, all especially for planting in the KKL-JNF forests of the south.

Fruits of the Ziziphus spina-christi, known as the Christ's thorn jujube tree. (Photo: KKL-JNF Photo Archive)

The seedlings destined for planting in the southern region (which ranges from the Ashdod-Yavne-Beit Jubrin area all the way down to Eilat) are grown from local seeds in order to ensure their genetic suitability for local climes and conditions. This significantly boosts seedlings' chances of survival and sometimes even their resistance to area pests and diseases.

The selection of trees for planting depends on soil type and other factors regarding the area in question. Soil types can vary even within the same forest, Chercasky explained, with some areas retaining more water than others. The trees are usually planted when they are larger and more mature (and are harder to steal), and then they are irrigated; three times during their first year, twice in their second year and only once by the third year. Then they must rely on the nature for its irrigation, from which they can expect an average yearly rainfall of 240 mm.

Chercasky at the Plant Seedling Cultivation Plots. (Photo: KKL-JNF Photo Archive)
"The most important thing for planting in the southern region is to pray for rain,” Chercasky quipped.

To maximize the area's meagre rainfall, KKL-JNF relies on two simple water harvesting techniques based on ancient agricultural methods used in this very region. The first is by use of a liman, a shallow dam dug in a gully or riverbed that traps water from flashfloods so that it can permeate the slow-to-absorb soil. Tree groves are planted specifically in the flooded area of the dam, with an overflow channel regulating the level of accumulation. The limans create artificial sinks that prevent loss of surface runoff, topsoil and nutrients while also stimulating growth of natural vegetation.

The second water-gathering method used by KKL-JNF are the shikhim - narrow terraces with raised edges dug into the hillside. The shikhim also prevent water runoff and topsoil erosion, but unlike limans that receive large quantities of runoff water infrequently, the terraces receive smaller quantities of water at more frequent intervals.
Trees ready for planting. (Photo: KKL-JNF Photo Archive)

In addition, KKL-JNF forest workers control weeds around the saplings, either manually or by using herbicide, said Chercasky. One of the main problems encountered when planting trees in the south is the high salinity of the soil, which is characteristic of the Negev-Arava region, he added. “If there is salt in the soil and it isn’t washed away when there is rain or when the tree is irrigated, the salt can collect and pool around the roots and kill the tree,” he said.

The tree saplings are grown in a moss peat mixture which, when dry, is very hard to moisten, so it is vitally important to control the rate of moisture the tree receives, in order for the material not to dry out before the roots have had a chance to grow and spread. The tree's potential size is also considered when planning an area for planting, so as not to create a situation in which too many trees compete for the same soil, water and sunlight.
KKL-JNF workers nurturing the saplings. (Photo: KKL-JNF Photo Archive)

For the past two years, KKL-JNF Southern Region has been concentrating on planting trees in the Omer Forest, which stretches from the town of Omer northwards to Yatir. The better-known Yatir forest, the oldest forest in the south, has already reached its optimal size.

Already at the end of every planting season, KKL-JNF foresters and professionals begin planning the next season's plantings, in order to prepare the soil and water sources needed for the coming season.

“We go to places where there has been no planting before, such as in Omer Forest, where there is a big area where we do lots of planting,” Pablo Chercasky said. “We plant the trees for the sake of all the residents of the area; to prevent the topsoil from getting washed away by the rain, to provide shade and grazing for shepherds, and to provide everyone here with a better quality of life.”

Growing saplings at the Gilat nursery. (Photo: KKL-JNF Photo Archive)