Statistisch onderzoek naar de samenhang tussen het weer, de grasproductie en de melkaanvoer

A study was made by calculating correlation and regression coefficients, and by rising frequency diagrams of the relation between the weather factors temperature (mean daily temp. taken from observations at 8,14 and 19 hours), cloudiness and number of days with at least I mm precipitation, and the production of grass (first cut in June) and the milk supply during June-September.

Independent of soil and the differences in climatic circumstances, a reliable positive correlation was found between the grass production and the number of days with precipitation and cloudiness during the period 1 May-10 June. In this period there was a negative correlation with temperature. From data obtained from the western part of the Netherlands a reliable positive correlation was found with temperature during the winter.

The milk supply during June-September was positively correlated with number of days with precipitation and cloudiness in the months July and August. The correlation with temperature in these months was negative.

Reliable correlations were found in May in districts where grazing in the weeks before mowing caused risk. The correlations with cloudiness and precipitation were positive, while those with temperature were negative.

Otherwise the correlations in May were unimportant as was expected.