ON THE GROWTH OF LEGUMINOUS CROPS. 



25 



PRODUCE OF NITROGEN IN THE MIXED HERBAGE OF GRASS LAND. 



The results in Table XI. afford evidence in the same direction. 



TABLE XI. 

 EXPERIMENTS ON THE MIXED HERBAGE OF PERMANENT GRASS LAND. 



The Park, Rothamsted. 



Results showing the effects of Potash, on the development of Leguminosse, and on the 

 yield of Nitrogen in the crops. 



* Plot 4-1, botanical separations at 4 periods only, namely 1862, 1867, 1872, and 1875. 

 t Including Potash, 6 years, 1856-61, excluding Potash, 14 years, 1862-1875. 

 J Including Potash every year. 



As stated in the title of the Table, the results show, in the case of 

 experiments on the mixed herbage of grass-land, the effects of potash 

 on the development of the Leguminosee, and on the yield of nitrogen in 

 the crop. Results are given for four plots one without any manure ; 

 one with superphosphate of lime alone ; one with a complex mineral 

 manure, including potash for six years, but excluding potash for the 

 succeeding 14 years ; and lastly, one with the complex mineral manure, 

 including potash every year of the twenty. 



The first set of three columns shows the average percentage of 

 gramineous, leguminous, and miscellaneous herbage, in the produce, 

 according to botanical separations made in six, or in four seasons, as 

 stated ; the second set the average produce per acre over 20 years, of 

 each of these descriptions of herbage ; and the last three columns show 

 the amounts of nitrogen, per acre per annum, in the mixed produce, 

 over the first 10, the second 10, and the total period of 20 years. 



It is seen that on plot 8, with only a temporary supply of potash, 

 the percentage of leguminous herbage in the produce is higher than on 

 plot 4-1 with superphosphate of lime alone ; but that, on plot 7, with 

 the continuous supply of potash, it is more than twice as high. Thus, 

 the percentage of leguminous herbage is on plot 4-1, 5 '68 ; on plot 8, 

 8-43; but on plot 7, 19'13. 



The middle column of the second division shows that the estimated 

 amounts of leguminous herbage per acre per annum were on plot 4-1 

 without any potash 142 Ibs., on plot 8 with partial supply of potash 

 285 Ibs., and on plot 7 with the continuous supply 757 Ibs. 



D 



