ow do you persuade an olive grower who has watched his father and his grandfather pruning their olive trees vigorously that, maybe, a lighter pruning will bring more rewarding yields? Or that following the contour line with the plow might stop his topsoil from slipping downhill into the field of an appreciative neighbor?
        Slowly, very slowly and patiently, is the answer. And there has to be a lengthy period of confidence building. There is little point in a 'know-it-all' scientist breezing into a village in northern Syria, decrying local husbandry practices, and announcing "This is how it's done!" before zooming off in a cloud of dust to the next group of perplexed growers.
        After all, respond the farmers, what can someone who arrived only yesterday know about the fields, soils and trees a family has nurtured for generations?
        Sadly, that care and nurturing is often misguided. Getting the message across in an acceptable manner becomes more important than the message itself when the scientist knows that a slight shift in the pH of the soil will unlock a valuable trace element of long term benefit, yet the grower sees no immediate return.
        Confidence building was a key element of the farmer-participatory research carried out by ICARDA's soil conservation and land management specialists at Yakhour in northwestern Syria. Since ancient times, the northwest has been the olive zone in the country. The olive tree itself has a venerable history, with cultivation of olives in the region traceable back 5,500 years. The ancient Greeks considered the olive to be sacred and today the olive branch is still recognized as a symbol of peace and plenty.
        Olives and olive oil are fundamental elements in Mediterranean cooking. The oil is of high nutritional value, containing natural antioxidants which make it retain its fragrance and taste over long periods. For Syrian agriculture, in the west and northwest, olive trees are the major source of income for small-scale farmers. The area planted with olives has increased substantially in recent decades.
        However, traditional land-husbandry practices have not kept pace with the intensification and expansion of olive production into steeper areas. Because no land conservation measures are being taken, and intensive clear tillage leaves the land unprotected, soil erosion is evident everywhere.
        Only recently have farmers on the steeper hillsides become conscious of their increasingly unstable and declining yields. Because the degradation of the land had not been identified as a real problem, they have not devised the traditional terracing and other conservation-farming techniques found in other regions.
        The mountain village of Yakhour, where Kurdish immigrants first cleared the forest for agriculture in about 1920, is a typical example of land degradation in steep olive fields. There is a need for location-specific land conservation measures that protect the soil and, at the same time, enhance the productivity of the olive trees. A small project was set up to stabilize and improve the productivity of the olive trees which are grown here mainly for their 25-30% oil content. Most farmers also have one or two trees producing fruit for their own consumption but their prime market is for olive oil.

        Two village farmers, deliberately chosen because they were not the village's acknowledged top growers, each agreed to set aside an entire field for the experiments. Each field was divided into three sections, with 75 trees in each of the two system treatments and 50 in the farmer's own area. Each field was mapped intensively and individual trees identified. It was agreed that ICARDA would make up the difference if the trees in the four experimental treatment areas yielded lower than on the remainder managed by the farmers using their normal systems.
        All the work was carried out by the growers, although ICARDA provided regular backstopping, as well as the initial guidance on the treatments to be followed. These were kept relatively simple. Cultivation passes were reduced or dropped altogether since there was no obvious benefit from making three passes with a mule and plow, and indeed the extra disturbance was more likely to contribute to soil erosion. Chemical fertilizer was introduced but only two treatments also received additional animal manure.
        This organic manure will help increase soil organic matter content and lower the pH slightly. In the alkaline conditions (8+) prevailing on these slopes, phosphorus is locked up but will become more readily available to boost yield if the pH can be lowered in the long-term by as little as half-a-point.
        Various forms of soil erosion prevention were assessed, including vetch cover crops, small catchment barriers and non-tillage. Insect traps, with instructions to spray as necessary, were used on all the experimental treatments, but herbicide was allocated to just two. Light pruning was used, and nets placed under the trees at harvest to catch the fruit.
        Final assessment of the first harvests is still being carried out but the growers saw enough to convince them that yields are up and those compensation payments for low yields won't be paid out. Of their own accord, they and their neighbors are already incorporating some of the innovations into other fields to boost olive harvest.
        The experimental treatments are being continued with new growers to test them under as wide a range of conditions as possible. Measurement of the soil translocation is planned. Traditionally, farmers using mules have plow along the contour. However, since the advent of tractors plow downhill for safety reasons has become the norm on the steeper slopes where a top heavy tractor is less surefooted than the low-tech mule. This has added to the degradation bringing soil depth down from a meter or so to 25cm in places. However, with mules it is relatively simple to work across the contours creating individual tree terracing and incorporating enclosed areas for water conservation.

        The project has been supported by funds from the Spanish National Agricultural Research Institute (INIA). There are many lessons that can be drawn from Spanish experience, and the Forest Experiment Station in Granada has been particularly forthcoming with advice.
        Just as in Syria, the Spanish have difficulties persuading olive growers to maintain a cover crop between the trees. Farmers all over the world prefer to see 'clean' fields--free of anything a neighbor will disparage as a weed. But in Spain medicinal and aromatic plants--with a high income potential--have been planted along the contour lines to arrest erosion. The returns are high enough to offset any concerns about the cover competing with the trees for moisture. A herbicide applied after flowering can be used in rainfed systems and still leave the dead plant tissue to protect against run-off and raindrop impact.

        Early visits to the village to discuss all aspects of olive growing and management established that the main interest of the farmers was to secure and increase their olive production. Environmental concerns, such as soil erosion, had a low priority.
        The systems used for working the slopes varied according to gradient but there were common approaches too. Over the course of a confidence-building year, both deficiencies and plus points in the management systems used were teased out and examined.
        The Syrian Olive Bureau played a key role in demonstrating how changes in husbandry can have a worthwhile impact on the health of trees and their yield. The Yakhour farmers visited their counterparts in the lower-lying Idleb area southwest of Aleppo to see for themselves the benefits to growers there of using fertilizers and pesticides.
        This intensive interaction led to a formal meeting at the village school where the specialists summarized the information they had gathered, and outlined a modest joint research project to address all the issues and problems felt to be of importance to olive production in Yakhour. The aim was to try out and compare new ways of land management for the olive groves under real-world conditions in farmers' fields. It was important to demonstrate that soil conservation is an important part of an olive production system and that only an appropriate combination of all aspects of olive growing would lead to a more productive and sustainable use of the land.
        The careful preparation paid off. Now farmers were willing to volunteer their land to try out the two differing 'system packages' designed with their help. Both packages were aimed at combining the best possible crop husbandry practices, such as pest control and proper pruning.
        Olive trees - like many fruit trees found in suburban gardens - have biennial fluctuations in yield. Breeding can offset this but for 40-year-old established trees pruning is the best way to introduce more consistency in yield. Traditionally, the Yakhour farmers used a heavy, post-harvest pruning system but they saw the evidence of benefits at Idleb from waiting for a lighter spring pruning after the frosts have passed. This light pruning may give a slightly lower peak yield in years acknowledged to be high yielding, but in a poor year the grower can expect a higher than average crop.

        Another possible way to maintain a seed reservoir for the cover crop is to kill off only alternate strips of the cover vegetation. Some growers also use a herbicide pre-harvest to create an even mat on which to place nets for catching the fruit.
        One suspects that if the Yakhour growers could only make the trip to Spain there would be some very serious questioning of their Spanish counterparts and more than a few new ideas flowing back to the slopes of northwestern Syria.

Dr Michael A. Zöbisch, formerly Soil Conservation and Land Management Specialist with ICARDA, is Associate Professor, School of Environment Resources and Development at the Asian Institute of Technology, Thailand; Dr Zouhair Masri is National Professional Officer for soil conservation and land management at ICARDA.