172 FIELD CROPS 



cold, while light sandy soils are too Ukely to dry out when the 

 crop is in the greatest need of moisture. A fairly good crop 

 can be produced on almost any reasonably fertile land, how- 

 ever, if other conditions are right. Some of the heaviest 

 yields are obtained on the muck soils of Washington. 



The oat plant is a comparatively shallow feeder, most of 

 its roots being found in the first two feet of soil. For this 

 reason, the best crops are produced on fairly fertile soil, 

 though on rich land there is always a tendency toward rank 

 growth of straw, particularly if the moisture supply is abun- 

 dant. This rank growth and abundant moisture invite 

 such diseases as rust and mildew, and the weak, soft stems 

 are unable to support the weight of the crop, hence lodging 

 follows. If lodging takes place early in the season, the grain 

 will be Ught and' fehriveled. Lodging when the grain is 

 nearly ripe usually does little damage to the crop, though 

 the cost of harvesting may be greatly increased. Lodging 

 at this time is more likely to be due to the blowing over of 

 the entire plant during a heavy rain storm than to weakness 

 of the straw. Attempts are being made to produce oats 

 which are resistant to the tendency to lodge, but the most 

 effective means of preventing lodging are thorough drainage 

 and the use of land that has not been freshly manured. 



210. Manure and Fertilizers. It has just been stated 

 that the land should not be too rich for oats. It is best to 

 apply barnyard manure to some other crop in the rotation, 

 such as corn or grass, allowing the oats to get some of the 

 benefit of the residual effect of the manure. When com- 

 mercial fertihzers are necessary, those containing phosphorus 

 and potassium as the principal elements should be used, 

 except on soils which are decidedly lacking in nitrogen. On 

 such soils, plowing under a leguminous crop for green manure 

 before sowing the oats is frequently of much benefit. This 

 is most necessary and can be done to best advantage in the 

 South, where oats are sown in the fall. On soils which are 



