The Hop-Growing Year: The Soil*
Good soil fertility is important
It is necessary to work the soil so that the hop hill can form summer roots (adventitious roots), the weeds are destroyed and the soil loosened and aerated. Rape is sown in July between the rows to improve the soil fertility. After the hop harvest the rape forms dense growth and protects the soil from erosion. At the same time it supplies organic material for the formation of humus and is a nutritional basis for the earthworms. The rape remains standing throughout the winter and is spread over the ground in April before it flowers.
Trials have shown that when the soil is frequently worked it is in fact a cheap way of controlling weeds but encourages the decomposition of humus as well as erosion. Therefore the object of working the soil should be to spare the humus reserves and at the same time control the weeds. In other words - as little soil work as possible but as much as necessary.
Green manure diminishes erosion and nitrate scouring
Hop yards on hillsides are at risk for erosion. By covering the ground it is possible to reduce a considerable amount of soil being washed away. At the same time the green manure over winter reduces the amount of nitrate scoured.
Hops produce a great amount of plant material within a short time and at the same time extract a great amount of nourishment from the soil. In order to obtain a permanently high yield these nutrients must be returned to the soil. Regular soil tests are a precondition for accurate fertilization according to the hops' requirements. In addition to this, a regular supply of organic matter is needed for the formation of humus to maintain the soil fertility. The hop-grower therefore fertilizes regularly with organic fertilizers and with mineral fertilizers to supplement the lack of nutrients.
Principles for the use of fertilizers
- Optimum utilization of nutrients through well-targeted distribution as far as time and quantity are concerned.
- Avoiding loss of nutrients via groundwater, surface scouring and gaseous losses.
- Apparatus for spreading the fertilizer must guarantee exact quantities dosed, accurate distribution and low losses in spreading the fertilizer.
° © Extract from the LfL - Bavarian State Research Centre for Agriculture