Corn Grotvers' Association. 175 



A few years ago the Experiment Station, co-operating with 

 the farmers of Missouri, started a number of alfalfa experiments 

 covering all of the soil types of the State with the idea of deter- 

 mining the best methods of securing a stand on these different 

 soils. The results of these experiments show that a distinct rela- 

 tion exists between soil types and the successful growing of this 

 crop, and it is the purpose of this paper to discuss this relation. 



ESSENTIALS ARE: DRAINAGE, RICH SOIL AND INOCULATION. 



There are perhaps three essentials to the successful growing of 

 alfalfa — drainage, rich soil and inoculation. This crop needs a 

 deep, loose, well drained soil. Alfalfa roots go deep into the soil and 

 the plant gets moisture from below. For this reason it thrives so 

 well on the semi-arid regions of the west. On wet lands where 

 the underground water is near the surface the plants never do 

 well and soon die. Alfalfa is not grown successfully on our flat 

 prairie soils, which are poorly drained. These soils are underlaid 

 with a stiff clay subsoil in which the water level fluctuates, often 

 rising on the roots and drowning out the plants. 



Another requisite for the successful growing of alfalfa is rich 

 soil. Especially is this true in starting the crop. It may be 

 started on thin land deficient in humus and nitrogen but which 

 contains a sufficient supply of mineral elements of plant food, but 

 under such conditions it starts very slowly and will rarely pro- 

 duce profitable crops. In practically all such cases, however, crab 

 grass and foxtail will come in so thickly as to crowd out the alfalfa 

 before it can develop a good root system and become supplied with 

 nitrogen-gathering bacteria sufficient to make a thrifty growth. 

 In Missouri, where the conditions are not so favorable for alfalfa 

 as in the west, it is necessary for the plant to get a good start 

 from the first, and hence a rich soil is necessary for its growth. 

 Alfalfa is a heavy feeder on nitrogen and phosphorus — two ele- 

 ments that are deficient in most Missouri soils. It is also a rather 

 heavy feeder on potassium, but there is an abundant supply of this 

 element in most of our soils, so nitrogen and phosphorus become 

 the limiting elements. On the upland soils, then, an application of 

 manure, and in some cases manure supplemented with bone meal, 

 has been found necessary to secure a good stand. Manure fur- 

 nishes the young plant with nitrates until it can become well 

 established in the soil and supplied with its own nitrogen-gather- 

 ing bacteria. On the better soils, however, where the plant food 



