This is by no means a new concept in agricultural practices. It is one of the oldest and most effective control strategies, allowing the fields to be in almost continuous production, while controlling crop damagingpests.
The usual model for crop rotation covers a two to three year rotation, and may include a year of summer fallow (no cultivation) for each field at some point in the rotation.
Generally the rotation will begin with a leafy crop the first season, then vegetables, followed by root crops, legumes and then grains. Best practices dictate growing legumes to replenish the soil before grain crops, and the practice of green manure , that is, planting a deep border of rye around a field, which is then plowed under after the food crop is harvested, to add nutrients to the soil. Sometimes a whole field might be put to a green manure crop to renew the soil.
Some of the advantages of crop rotation include the prevention of soil depletion which is common in monoculture food production. Large fields of waving grain may look picturesque, but they require intensive applications of chemicals such as fertilizers and herbicides to keep down the weeds, as well as pest controls. Crop rotation helps reduce this reliance on chemical applications.
As you can see, though, this is a fairly labor intensive method of crop production, and a far cry from the commercial farming now carried out in much of North America’s “bread basket”.
This refers to the practice of seeding directly into the undisturbed stubble of the last season’s crop. This allows for an immense savings to the farmer in terms of fuel and equipment use (and repairs), instead of requiring the expenditure of time, energy, and valuable resources tilling the field to ready it for the next crop.
Originally suggested to help prevent soil erosion due to over-cultivation, this practice has been slow to catch on in some areas. This is due in part to the problem of weed control, particularly in the use of some grain crops that have been altered to accept only a specific weed control agent, such as “Round-Up Ready” crops.
Studies under many weed management programs have shown however, that converting from conventional to zero tillage would require relatively minor changes to the overall weed management program to achieve the same results as with conventional tillage and weed control measures.
The benefit of switching to zero tillage for the appropriate crop and field conditions is the potential to reduce agriculture’s impacts on the environment and lower energy and labor costs.
Encourage & Maintain Biodiversity:
One of the most important initiatives currently underway is the effort to maintain diversity in our food sources. In my own lifetime, the model for modern food production has changed from the family farm to huge, monoculture businesses sprawling across the landscape.
In my now-home province, once dotted with grain elevators from a variety of prairie grain Co-Operatives, the only signs visible across much of the south are centralized plants bearing the trade name of Agricorp, one of our current agricultural giants.
Tomatoes, now grown thick-skinned and picked grossly under-ripe for ease of harvest, shipping, and storage, only come from one or two strains. The carrots, straight, long and bright orange, in your local grocery chain may have only one or two parents, instead of the myriad varieties we once grew and prized for their different flavors and uses.
In breeding for the perfect looking and keeping carrot, the tomato that will better survive shipping, we are creating an artificial standardization, and losing many species in the meantime…and these are only a few examples of how our modern practices are depleting the biodiversity of our food crops.
If the engineered food crops on which we now depend ever experience a serious threat, one which we are unable to combat, we will lose whole categories of foods, resulting in wide spread famines. Some scientists predict global famines because of the loss of biodiversity.
To prevent this, many countries have established Food Grains and Genetic Material Banks to preserve samples of vanishing food crops. These seeds are revitalized on a regular basis to ensure viability by planting some of the preserved seeds and harvesting and preserving the new seeds that are produced.
In addition to seeking alternatives for chemical agents in controlling weeds and crop pests, and developing regionally targeted crops to give higher yields with less environmental stress, one of the thorniest issues facing all the stakeholders in any discussion of sustainable agriculture is the need to reassess local and regional policies for land usage.
I can think of quicker ways of committing political suicide, but none so sure as to institute a discussion of land use.
However, that is exactly what we must do…and soon.
Valuable lands are being stripped of their top-soil to make way for urban growth – for housing developments that are sorely needed. We will never be able to reclaim that land for the production of food. Family farms are being lost to huge conglomerates that deplete the very lands they use to feed us, while consuming resources at an astronomical rate.
It seems ironic that our ancestors came here for the rich farmlands, built towns to sustain all the folk drawn here by the land, and now we are burying those same lands under the cities that grew up because of them.
The country in which I live is rich in natural resources, yet we are turning those resources, our rich farmlands, into tracts of houses that will yield nothing for future generations except perhaps a real estate deal, and into sanitary landfills to bury the unsightly wastes we produce from those houses.
This problem is not limited to my home – it is become endemic in North America, and many other parts of the world, and we must begin to undertake these discussions while there is still arable land to protect.