Jan. 1922] annual report. 17 



Soil Rejuvenation Study. 



Numerous inquiries relative to the use of green manure crops have added 

 emphasis to the fact that many acres of possible tillage land in New Hamp- 

 shire are becoming depleted in nitrogen and organic matter. 



Recognizing the possibility of correcting some of these deficiencies by means 

 of green manures together with certain mineral fertilizers, a series of plots 

 covering two acres of an old hay field were laid out in the fall of 1920 by 

 Messrs. Eastman and Kraybill. These plots are on a sandy loam soil, are 

 one-quarter acre each and are run in duplicate. Previous to the planting 

 of the plots, the soil was analyzed for acidity and was found to have an average 

 lime requirement of nearly 3 1-2 tons of ground limestone per acre. The 

 entire plot was limed on this basis. 



The plots are treated as follows : 



No. 1. — Fall plowed and seeded to rye and vetch; this crop 

 plowed under in the spring and seeded to oats with clover 

 and timothy. 



No. 2. — Fall plowed and seeded to rye and vetch; this crop 

 plowed under in the spring and seeded to oats and peas to 

 be plowed under in late summer and again seeded to rye and 

 vetch to be plowed under the following spring, at which time 

 the plot is to be seeded to oats with timothy and clover. 



No. 3. — Same as No. 2 except that buckwheat and soy beans 

 are substituted for oats and peas in the series. 



No. 4. — Fall plowed and seeded to oats with clover and timothy 

 the following spring. 



In order to study the effect of certain mineral fertilizers each of the fore- 

 going plots was divided into five sections which were treated as follows: — 



(a) With raw rock phosphate and gypsum. 



(b) With acid phosphate. 



(c) With nitrate of soda, raw rock and gjrpsum. 



(d) With nitrate of soda and acid phosphate.  



(e) No treatment. 



A similar series of tests was begun on a second two-acre tract in the fall 

 of 1921. This second tract is a heavy boulder clay soil, low lying, and has 

 not been plowed or fertilized for more than forty years. 



On the first tract poor yields of rye and vetch were secured the first season. 

 The buckwheat made a fair growth but the yields of soy beans and oat fodder 

 were very light. 



Sunflowers for Silage. 



This was the third season that Mr. "taylor has tried sunflowers out as 

 a silage crop. The yield per acre on the plot this year was 22.58 tons per 

 acre. This is about 70 per cent, greater than the average yield of the several 

 varieties of corn. The sunflowers were planted thicker than usual and made 

 a good yield of average size stalks. Our results indicate that where corn 

 cannot be successfully grown, the sunflowers furnish a good substitute as a 

 silage crop. The quality of the silage as indicated in our first year tests 

 was almobt as good as that of corn silage. Even where corn can be grown 

 successfully it would seem that sunflowers mixed in with it will increase the 

 yield, particularly on "witchy" ground. 



