ANRA:Textbook:Crop Rotation

Crop rotation

by Sion Ju'un, ranger of Pelar, She'mathen Le'yeritath

Introduction:

Crop rotation is planting specific plants in preplanned order on the same field. Each succeeding crops must be of all together different type than the previous crops planted. Crops must be rotated on a three to four year cycle. Different crop must be planted every year. Crop rotation will maintain soil fertility, reduce erosion, reduce damage from pests, reduce damage from weather and increase crop yield.

Benefits of Crop Rotation:

Maintaining Soil Fertility.

Every crop requires different minerals from the soil. If same crop, for instance corn, is planted year after year, over time the soil is depleted of the minerals needed for growth. Some of the minerals can be returned by manure but it is not cost effective and often not as goods as well planned crop rotation. A different crop can return minerals used by another crop back into the soil as the plant dies and are returned to the soil.

Pest and Disease Control.

Many insects only target single plant type for food source. They also lay eggs and burrow into the leaves and vines of plant. As you till, and plow your farm, some of those insects will enter the soil and spend winter in the soil. Only to return in the spring to re-infest, if you plant same crop year after year. Crop rotation can prevent this by introducing crop that is not target of the insect that infested previous crop. Just like the insects, plant diseases often target specific plant type. Crop rotation will prevent damage from disease just like it protects from insect damage.

Reducing Soil Erosion.

Some crops, while it yields large amount of product, are susceptible to cause soil erosion. Several factors are involved, wind, water retention and sun light reaching soil. Plants such as meadow and small grains can prevent that from happening.

Increased Yield.

Planting different crop in sequence often results in higher yield when it is compared to continuous planting of same crop. For example, planting wheat on a field previously occupied by barley will result in higher grain yields when it is compared to continuous planting of wheat.Even higher yield can be observed by two distinctly unrelated crops, such as small grain crop planted into field where the previous crop planted was legume, flax or sunflower. Although why higher yields are obtained by rotating crop is not mostly understood, it has been observed that it does work.

Selecting Crops to be used in Crop Rotation:

When selecting crops for rotation, several factors must be considered. The long term viability of the rotation to reduce insect and disease damage, ability of the crop to grow in the climate, soil condition, as well as economic factors must be considered. Further research of M'Chek climate condition, soil type, common plant disease, insect and other factors must be conducted before specific model of crop rotation can be designed.

Plant family.

It is important when designing crop rotation to select plants that does not share similar traits. Below are some examples of crop that belongs to different family of plants.

Beet root family- Beetroot, Spinach Potato family- Pepper, Potato, Tomato Carrot family- Carrot, Celery, Fennel, Parsley, Parsnip Onion family- Garlic, Leek, Onion, Shallot Marrow family- Cucumber, Marrow, Pumpkin, Squash Pea and Bean family (Legume)- Alfalfa, Pea, Lupin, Clover, Beans Daisy family- Lettuce, Chicory Cabbage family- Broccoli, Cabbage, Cauliflower, Kale, Radish, Turnip Other- Corn, Rye, Buckwheat, Grains

Sample Crop Rotation Model.

Below are examples of possible four year rotation models. Rotate plot from A to D if plot is set up in following fashion.

Plot A Plot D
Plot B Plot C

Model 1.

Plot A. Marrow family (manure)
Plot B. Pea and Bean family
Plot C. Cabbage family (lime)
Plot D. Root crops/Onion family (leafmould)

Model 2.

Plot A. Potato family (manure/compost)
Plot B. Pea and Bean family
Plot C. Root crops/Onion family (leafmould)
Plot D. Grain crops (compost)

Soil maintenance.

Some additional minerals may need to be added to the soil for optimal yield.

• Manure and compost - Apply for Potato family, Onion family and Marrow family as needed. Don't use it on Carrot family or Beetroot family.

• Lime - Beneficial for Cabbage family, if applied in the autumn before planting them. Never use it on potato family.

• Leafmould - It could be used on any plants, but most beneficial for root crops and Onion family.

Related Links

• Academy of Natural Resources and Agriculture
• Irrigation
• Soil and Water Conservation
• Problems associated with Farming