Valuable nutrients equally distributed - the base for high earnings

Spreading mistakes due to inadequate settings and maintenance of the spreader still occur frequently in practice. Unevenly spread nutrients have a negative impact on the yields and quality of harvestable products and make the inventory management as well as the harvest difficult. For the practical farmer it is important to know the criteria affecting the quality of the spreading pattern in order to be able to react on this when appliying the fertilizer.

In der heurigen Düngungssaison sind Landwirte mit hohen Düngerpreisen konfrontiert. Bei den derzeitigen Preisen für agrarische Erzeugnisse ist jedoch jedes Kilogramm Mehrertrag ein positiver Beitrag zum betriebswirtschaftlichen Optimum. Neben einer Neuausrichtung der Düngungsintensität, die sich vor allem in Gunstlagen trotz deutlich gestiegener Düngungskosten auf höherem Niveau als bisher bewegen wird, spielt eine optimale Ausnützung der gedüngten Nährstoffe durch den Pflanzenbestand eine wesentliche Rolle. Eine gleichmäßige Nährstoffverteilung beim Streuvorgang ist die Basis dafür.

Impact of spreading mistakes on the yield of the grain

Basically the spreading failure is indicated as coefficient of variation  (variation from the median in %) of the spread fertilizer amount over the working width. A spread image is assessed as "very good" if the spread failure is below 10% and as "good" if the failure is below 15%. Spread failures below 25% are in practice with "freiem auge" not visible but already have an impact on the development of the yield of the grain (table 1). If considerablly different green coloured stripes can be observed in the standing crops ("technical stripe disease") or in the extreme case in the grain at stock, the spread failure amounts to 50% (pictures 1 and 2). Losses of 1000 kg/ha are the consequence.

spreading fields in % yield dt/ha yield deficit dt/hat
0 83,7
10 83,3 - 0,4
20 82,0 - 1,7
30 79,9 - 3,8
50 73,2 - 10,5

Yield loss of wheat dependent on spread failure (28 trials, BASF Limburgerhof, 1986-1998)