Rotation of Crops

ROTATION OF CROPS. Rotation of crops cannot be planned and executed successfully without, at the same time, giving consideration to all other factors affecting successful farm ing. These are: (I) the crops and live stock that are naturally and economically adapted to the locality; (2) the type of farming best adapted to the size of the farm; (3) highest-profit combi nation of crops; (4) the economic balance of crop production with live stock; (5) the system of farming that best controls costs and best distributes power and labour demands throughout the year; (6) the maintenance of soil fertility; (7) the place given to less profitable enterprises in providing a better balanced business and in utilizing all the available resources; (8) the selec tion of high-yielding varieties, the control of plant and animal diseases and insects; (9) the production of high-quality market able products; (io) the consideration of short-time adjustments in production, to meet market conditions without disrupting the planned economic procedure.

Every farm has some kind of cropping system, whether it be a single crop grown year after year on the same land, or several crops that change from field to field. It is only, however, when a series of crops are grown one after another in regular and orderly fashion, that there exists a crop rotation. While the more essential reasons for following a crop rotation hold in most localities, the most profitable combination of crops and live stock for different regions shows wide variation. In an eastern corn belt area of the United States, a comparison was made of the variation over a seven year period in the number of acres of crops on the successful and unsuccessful farms. This showed that the varia tion in crop acreage from year to year was much greater on the unsuccessful farms. The good farmer follows a well-considered plan of cropping his land.

Classes of Crops to Include in the Rotation.

In general a crop rotation is made up of three classes of crops, namely: (I) cultivated or intertilled crops; (2) small grain crops; (3) grass, or leguminous crops, grown in the order named. Some of the oldest observations in agricultural practice have shown the in fluence of a preceding crop on a succeeding one. It is also well known that certain legumes have a beneficial influence on crops succeeding them, and sometimes on the crops that accompany them. Poor lands that remain in sod for a few years are improved in physical condition and producing powers. Soil fertility can, therefore, best be maintained when the three classes of crops are grown in order and in recurring succession.

How to Plan a Rotation.

In planning a crop rotation, b. rough map of the farm, showing each field, its acreage, and what crop is growing on it, should be made. If there are too many

small fields, too few acres in leguminous crops, or other deficien cies, the map will help locate them. The number of fields and the number of years in rotation should correspond, if possible. Sometimes it is advisable to have two independent or separate rotations on the same farm. The varying conditions which exist on a farm with respect to soil, feeding requirements, etc., may call for a flexibility in cropping system, in order that the highest success in farming may be realized.

The cultivated crop or crops included in the rotation will give a chance to kill weeds that may become bad where uncultivated crops are grown. Since some weeds are much worse in cultivated crops, while others are worse in small grain or sod crops, they can be more easily managed by alternating these crops. Cotton, corn and potatoes represent the three cultivated crops that occupy the largest crop acreage. There are many others used in different areas that must be considered in planning a crop rotation. The important small grain crops are wheat, oats, rye and barley. The third essential class of crop to consider for the rotation is that of the grasses or legumes. These crops have the larger growth near the ground and when turned under are valuable for green manure. This supplies the soil with organic matter, makes more moisture available to crops in dry years, helps get rid of excess moisture in wet years, and will help check erosion of hilly or sloping lands and make all lands more easily tilled. Also by alter nating deep-rooted and shallow-rooted plants, the plant food can be taken from different depths in the soil. Further, many plant diseases and harmful insects can be controlled by the practice of crop rotation. The distribution of labour and the amount and cost of equipment are also important considerations. The acreage and proportion of different crops must be so adjusted that the available labour can handle most of the work.

Applying sound business principles in determining the crop rotation is the key to its successful establishment and mainte nance. The benefits accruing may be summarized as follows: the good crop rotation (I) takes care of and improves the soil; (2) helps control weeds, destroys insects and plant diseases; (3) sup plies and removes plant food more evenly; (4) often results in saving labour; (5) aids in economical use of land, labour and capital; (6) makes farming more systematic; (7) when planned and developed with sufficient elasticity, adjustments can be made in acreages of cultivated crops, small grain crops or grass crops, to take advantage of market conditions. (H. M. Di.)