Continuous production of food without efficient and effective supplementation with fertilizers (organic and inorganic source) renders our soils non-fertile and incapable to hit our target in terms of yield and, profit margins. Reckless use of our land resource has resulted in adverse constraint on humanity and our respective environment. With vigilance, the challenges can be curtailed for us to realize good fauna and flora populations in our soils which in turn can help us reduce our input cost whiles achieving the most with little capital. This life changing phenomenon can be attributed to none but CROP ROTATION. This method of farming was what our early generations resorted to and helped them sustain the soil physical and chemical properties we are enjoying today. It is of no doubt that, this current generation cannot suffice with the same method, should we be self-sufficient in our food production. However, we have no one to blame for the adverse effects we are invoking for ourselves and the generation unborn through the careless use of our lands (soil). With an optimistic approach, we can re-invent this method of farming regardless of land sizes at our disposal. Now, permit me to rekindle our thoughts on this sustainable approach and decipher the nitty-gritty of practicing this phenomenon.
Crop rotation is a method of farming where a series of diverse types of crops are grown across a sequence of growing seasons in the same area. Crops are grouped into families, namely, Cucurbits, Brassica, Solanaceae, Legumes, Alliums, Umbelliferae, and Chenopodiaceae. This classification was done to curtail the occurrence of crop pests and diseases from spreading as they build up in a localized area. Hardly will you find pests and diseases of one family/group affecting another group, by so doing, we break resistance among crops grown in an area. Also, the continuous growth of crops in the same family brings widespread of pests and diseases. For example, nematodes that affect potatoes (Solanum tuberosum L and Ipomea batatas) can also infect tomatoes (Solanum Lycopersicum) which are all in the same family. Being a farmer with this knowledge can pre-inform our decision in replacing or following such crops with those from a different family. Moreover, crops from a particular family open the soil, others fix nutrients, cover crops to hold soil particles together, serve as host and biological control organisms, all these come together to provide a comprehensive approach to sustain our soil resources for progressive use.
These are some common diseases that run through crop families, and this is a caution to us in our decision-making so that we do not follow crops from the same family with each other.
To make this approach more practical, it is prudent to get us into the loop with some guidelines, so that we can achieve the three main importance of this method of farming.
1. Vegetables that feed near the soil surface, like corn, should follow deep-rooting crops
2. Vines or leaf crops should follow root crops.
3. Crops of the same family such as cabbage, broccoli, kohlrabi, and others should not follow each other.
4. Fast-growing crops should follow those occupying the land all season.
5. Keep records of what happened, and then make use of this information when planning next year’s crop.
These are the guidelines which should determine the rotation to be followed in individual cases. The proper way to address this matter is when making the planting plan.
To make things clearer, we can refer to this template for assistance. All the above guidelines have been put into consideration to generate a simple plan like this.
Based on the above scenario, we can now describe crop rotation to consist of this three main importance.
1. Prevent the spread of pest and Diseases
2. Avoiding soil nutrient depletion
3. Weed suppression
SPREAD OF PEST AND DISEASES
Continuous growth of crops from the same family renders the area prone to specific pests and diseases that affect the same family crops. In such cases, it is exceedingly difficult to break resistance no matter how powerful your control methods are. Having crops like tomato and pepper planted in the same area, you have little or no control over the presence of thrips, whitefly, and aphids, just to mention a few. Because they are all from the same family, tomato following pepper will still have the pervasiveness of these insects and their respective diseases they transmit as vectors. Meanwhile, following Solanaceae crops with Brassica will break the pest and disease cycle since diseases like Tomato Spotted Wilt Virus, TSWV (transmitted by thrips) does not affect cabbage nor broccoli. Also, Tomato Yellow Leaf Curl Virus, TYLCV (transmitted by silverleaf whitefly) does not affect most crop families compared to the Solanaceae. The practice of crop rotation, hence, reduces the cost of production since farmers utilizing this method would not have to buy Emamectin benzoate, Imidacloprid and other insecticides to control these pests and their respective diseases. By so doing, we save lots of money for productive use.
SOIL NUTRIENT DEPLETION
Continuous production of crops (shallow, moderately deep-rooted, and deep-rooted)-nutrient absorbers depletes the soil and make it non-fertile over an extended period if their planting is not planned and strategized. After every production cycle, shallow feeders, and heavy feeders (moderate and deep-rooted) under traditional, productive, and intensive approach averagely removes nutrients according to the table below.
Having considered the overview stated on the table above, for us to always have nutrients available for crop growth and development, our planting pattern should always be adjusted to make sure antecedent crops have the potential to supply nutrient reserves for the ensuing crops. Overlooking this principle to plant heavy feeders year after year invokes a lot of input capital by supplementing nutrition with organic and inorganic fertilizers (if available) whose prices are skyrocketing now. Meanwhile, replacing deep-rooted crops with shallow-rooted crops (tomato to onion) welcomes the onion with well pulverized and burrowed soil crust which makes the onion bulb form nicely without penetration interference. Moreover, the antecedent crop also brings soil nutrients to an accessible zone through capillary action so that the posterior crop can have access to leached nutrients. Also, considering the nutrient removal status of each crop listed, we can imagine how much we need to invest in terms of fertilization before we can replace and balance the nutrients to meet their respective recommendation for growth and development.
Certain families like legumes (beans) when incorporated into our crop rotation regime fixes nutrients, binds soil particles together, and covers the surface of the soil to provide an adequate temperature and humidity for our target crops. To add an icing to the cake, it prevents the soil surface from direct rainfall impact and runoff which washes away soil nutrients. All these combined provides an environment which inhibits the growth of weeds and some pests and diseases. By this end, farmers save lots of cost intended for Glyphosate, Nicosulfuran, Atrazine and 2-4-D to control weeds on their farms.
The choice always remains with us, whether to save cost, save the planet or expend while not reaching our yield target. If we are to make farming sustainable for our current utilization and attractive for generations unborn, crop rotation among other sustainable farming practices should be adopted regardless of our farm sizes so that we can achieve our SDG: GOAL 2, ZERO HUNGER by 2030 and beyond.