230 EXPEKTMENT STATION RECORD. 



A heavy application of phosphoric acid on the plat receiving a complete 

 fertilizer increased the absolute quantities of dry matter and plant food in the 

 fii'st half of the vegetative period and decreased the same toward the close 

 of the growing period. The lack of potash resulted in a marked tlecrease in 

 the absolute quantities of dry matter, nitrogen, phosphoric acid, and especially 

 in potash. The quantities of lime, on the other hand, were increased during 

 early growth when there was a lack of lime in the soil, but during the ripening 

 period a reduction took place and the quantity of lime in the crop on this i)lat 

 was smaller at this time than in the plants on the plat receiving the complete 

 fertilizer. An insufficient supply of nitrogen depressed in nearly all cases the 

 absolute quantities of dry matter, nitrogen, lime, potash, and phosphoric acid. 



In studying the influence of weather conditions it was found that the weather 

 had a modifying effect on dry matter production and also to a certain degree on 

 the use the plant made of nitrogen. No definite results with reference to potash, 

 lime, and phosphoric acid in this connection are reported. 



The results further indicate that in the early stages of growth, before the root 

 nodules have become active, a small application of nitrogen in a readily soluble 

 form would be very beneficial. Lime and phosphoric acid are needed during 

 the early stage and especially when the plant blooms and forms its fruit. 

 Potash is needed during the entire period of growth. It is stated that the bush 

 bean is adapted to the use of plant food supplied in barnyard manure and that 

 it is capable of using phosphoric acid given in slowly soluble form. 



Clover growing' on the loess and till soils of southern Iowa, W. H. Steven- 

 son and E. B. Watson (loira t<ta. Bui. US, pp. -'/-'/-6'(], fiys. 9). — Pot culture and 

 field experiments are i-eported, with suggestions regarding the growing of clover 

 in southern Iowa. 



In the pot culture tests 1 gal. pots were filled with soil and the effects of 

 manure and lime were studied. In the pot receiving manure at the rate of 16 

 tons per acre the weight of the crop was 45.9 gm., as compared with 8.8 gm. 

 from the untreated pot, the number of plants being 13 in each case. It was 

 found that lime was not beneficial on the soil used in the test, for a pot treated 

 with lime at the rate of 1 ton per acre showed little or no advantage over the 

 check test. 



The field investigations had reference to the effects of a nurse crop, manure, 

 lime, fertilizing material, time of seeding, and character of soil. Lime was 

 applied as finely ground limestone at the rate of 1,000 lbs, per acre, phosphorus 

 as steamed bone meal at the rate of 200 lbs., and nitrogen as dried blood at the 

 rate of SOO lbs. Mixed barnyard manure was used at the rate of 8 tons per 

 acre. Red clover was seeded at the rate of 8 lbs., alsike clover at the rate of 

 6 lbs., and oats at the rate of 2 bu. per acre. 



Clover when grown alone produced a yield from 2 to 4 times as great as when 

 grown with oats as a nurse crop. The plat seeded April 25 produced the heaviest 

 crop, but all were very satisfactory. Manure was decidedly beneficial, in one 

 case the crop being increased from 2,800 lbs. to 5,120 lbs, per acre. The use of 

 phosphorus gave nearly double the yield, while with potash the crop did not 

 increase either when it was applied alone or in combination with phosphorus. 

 With nitrogen, there was an increase of 1,800 lbs. of clover hay per acre over a 

 V)lat grown with the minerals without dried blood. It is advised, however, that 

 nitrogen should not be purchased in commercial fertilizing materials but should 

 be supplied in barnyard manure or in green manures. 



It was further shown that there is practically no difference in the relation 

 of loess and till soils of southern Iowa to the production of red clover. It was 

 observed that clover seed may be carried to the field by manure in such quanti- 

 ties as to improve the stand. While alsike clover was found well adapted to 



