38 



not injured by moderate frosts, and is therefore a nitrogen conserver ; it 

 is deep rooted and it grows so early and so rapidly in spring that a large 

 bulk of green material may be turned under in season for planting corn 

 and other crops which are planted at about the same time. If sown in 

 spring crimson clover will make one or more good crops upon suitable 

 soil. In order to secure more than one it must, however, be cut about 

 as soon as it begins to blossom. If allowed to ripen any seed it dies, 

 and in any event it will live but one season. Some recommend growing 

 crimson clover in this way in localities where when fall sown it is win- 

 ter-killed, but it can not be regarded as particularly valuable save where 

 it will pass through the winter. The quantity of seed required is about 

 twenty pounds per acre. 



The common, red, alsike and mammoth clovers are perhaps not in-op- 

 erly sjieaking catch-crops. They are, however, valuable crops for pur- 

 poses of soil impi'ovement, and since so much has been said in this paper 

 upon that subject it seemed desii'able to mention them. They are all 

 deep rooted, they take niti'ogen from the air, they conserve nitrogen, 

 they serve for winter protection of the soil, and must be looked upon as 

 among our most valuable crops for soil improvement. They are partic- 

 ularly deserving of attention on account of the large quantity of the 

 difterent elements of plant food left behind in their stubble and roots, 

 as shown by the table jireviously given. Methods of sowing and man- 

 agement are too well understood to demand attention here. 



Sweet Clover. — This crop is as yet but little known and cannot be 

 said to have passed through the experimental stage in this locality. It is 

 believed, however, that it may prove a valuable crop for soil improve- 

 ment. It takes nitrogen from the air, it is very deep rooted, it is hardy 

 in winter and will therefore conserve nitrogen and serve for soil pi-otec- 

 tion, it starts very early in the spring and grows with great rapidity. 

 On the tenth of June this year the average height in a field upon the 

 college farm was two and one-half feet, and at that time it was increas- 

 ing in height at the rate of an inch a day. Corn for the silo may be 

 put in from June 10 to 20 with every prospect of success, and it may be 

 doubted whether any nitrogen-gathering crop will furnish so much 

 green material to be turned in previous to these dates as will the sweet 

 clover. European experimenters report very favorable results from 

 green-manuring with sweet clover on heavy soils. In one experiment 

 in Germany, the results shown in the following table were secured 

 with oats : — 



Yield of Oats ami Straw per Acre with Different Manuring. 



Treatment. 



Grain 

 (Pounds). 



Straw 

 (Pounds). 



Without i;reen -manuring, no fertilizer, 1,099 



(hciri-iiiiiiiuring, no fertilizer, 1,64.5 



Grten-iiiaiuniug, 322 pounds Thomas slag, . . . . . 1,901 

 Without green-manuring, 161 pounds nitrate of soda (harrowed in), l 2,723 

 Without greeu-manuring, 161 pounds nitrate of soda (as top- 

 dressing), . . • • 1,591 



1,748 

 3,381 

 3,186 

 5,003 



3,455 



