Direct Seeding: The European Experience

Wolfgang G. Sturny

Plant Scientist and Tillage Specialist, Berne, Switzerland

European Farmland is increasingly being stressed with high axle loads and intensive soil tillage techniques. The structure of the soil is thereby becoming more and more unstable - causing lots of soil degradation problems - whereas, above all, its load capacity has to be markedly increased. Zero tillage - defined as a plant production system without any soil tillage from previous harvest to direct seeding - offers a solution to this dilemma: it goes easy on soil and water, at the same time it is labour-saving and cost-cutting.

In order to perform a sustainable and efficient agriculture, the European Conservation Agriculture Federation (ECAF) was constituted - but not until 1999! Actually, this non profit-making association counts six national member associations, including Spain, Italy, France, Portugal, Germany, and the United Kingdom. No wonder the European zero tillage surface still so small (cf. Table 1).

Zero tillage is a demanding system which requires some rethinking on the part of the farm manager. During the period of transition crop yields may fluctuate somewhat (cf. Figure 1), until about five years later a new "dynamic equilibrium" is reached in the soil - with a high porosity and earthworm population (cf. Figure 2). This was found on zero tilled plots of a demonstration experiment as compared to the plow treatment. The site is a medium textured soil located at a college farm close to Berne.

An equable crop rotation (alternating grain and foliage plants) is crucial for the success of a zero tillage system. It is also essential to maintain a permanent soil cover with straw, plant residues, and living plants as a basis for high soil biological activity, including efficient weed control - at the same time minimizing all pressure on the soil.

In order to promote conservation agriculture, an "incentive strategy" was adopted by the Bernese Office of Agriculture for regions susceptible to soil compaction, soil erosion, or nitrate leaching (cf. Table 2 and 3, respectively). For the same purpose on a national basis, a Community of Interests ["IG NO-TILL Direktsaat / semis direct"] was established four years ago. Actually we count 170 members. However, the total zero tilled surface in Switzerland corresponds to about 1.5% of the arable land (cf. Figure 3) - with upward tendency!

Table 1: Global zero tillage surface (in hectares)

• (Estimates by DERPSCH, 1999)

Table 2: Contributions for the transitional stage (canton of Berne)

• Requirements:

• during the 5 year-contract, at least 2 main crops have to be direct drilled (= zero tillage)
• zero tillage is defined as <50% soil disturbance from previous harvest to direct seeding
• plowing is forbidden
• a connecting contract for another 5 years can be concluded (with more strict conditions)

Table 3: The state of affairs on the performance of the decree on the retention of life basics and cultural landscape

(canton of Berne)

Figure 1: Long-term zero tillage experiment "Oberacker" (CH-Zollikofen): yields, 1995-99

Figure 2: Long-term zero tillage experiment "Oberacker" (CH-Zollikofen): Effects of Mechanical impacts on Earthworm biomass and water infiltration, 1998

Figure 3: Zero tillage surface of Switzerland (ha)

IG NO-Till Direktsaat www.no-till.ch