FACTORS LIMITING THE YIELD OF HAY 



AND THE ACTION OF PHOSPHATES ON 



HEAVY CLAY SOILS 



THE EFFECT OF RAINFALL ON THE YIELD OF 

 HAY FROM THE UNTREATED PLOTS 



I HE weight of the hay crop on the untreated plot at each of the 

 experimental centres varies within very wide limits from year to 

 year. When a dry season is experienced the crop is often a failure, 

 whilst the same plot given a moister and more favourable season 

 may reach the comparatively high production level of two tons to 

 the acre. 



In Table XL VII the yield of hay on the untreated plots for the 

 years 1916-20 is compared with the rainfall for the period May 1st 

 till harvest at the corresponding rainfall stations. The results for 

 four of the centres are shown graphically in Figs. 23 and 24. 



TABLE XL VII. COMPARISON OF THE WEIGHTS OF HAY ON THE 



UNTREATED PLOTS AND THE RAINFALL FROM MAY IST TILL 



HARVEST AT THE VARIOUS EXPERIMENTAL CENTRES 



* -71 inch of rain fell three days before plots were cut. 

 t 2-32 inches of rain fell on May 20th, 1917. 

 j -57 inch of rain fell two days previous to cutting. 

 Rainfall figures for period May 1st till June 30th. 



