An Intro to Crop Rotations

by Ailee Arias


Intro:


Long before the use of pesticides, herbicides, or synthetic fertilizers there was crop rotation. Basically meaning, planting different crops on the same ground to maintain or increase the soils productiveness. By cycling different plant families in the same plot of soil ensures nutrients are sustained, pest populations are controlled, weeds are suppressed, and overall healthy soil. Planting the same crops in the same area, year after year will allow pests to linger and multiply, and deplete the soil nutrients the crop is relying on. Therefore, the central idea is for the crops to sustain the soil themselves, as opposed to relying on synthetic fertilizers and pesticides - yucky gucky chemicals.


So without further or due we can indulge into this article by hitting these main points for executing your own crop rotations _へ__(‾◡◝ )> :

  • One more time, what’s crop rotation ?

  • Cycling out the families

  • Ze Power of Cover Cropping

  • Knowing your planting zones !

  • Along with doing strategic planning B-)

  • Last but not least : The Resources and References


One more time, what is crop rotation ?


A crop rotation is the practice of planting different crops sequentially on the same plot of land to improve soil health, optimize nutrients, and combat pressures of weeds and pests. By cycling out different crops, herbs, and tubers they are able to keep the soil lively by not letting certain pests build-up or let critical nutrients deplete.


For example, if a farmer has planted a field of corn, these crops consume lots of nitrogen and would be best to follow with a crop that will replenish these nutrients. Such beans, or plants from fabaceae are ideal for repurposing nitrogen through cover cropping, green manures, or growing as a cash crop.


The essential idea of cover cropping is for the plants to sustain the soil themselves through strategic planting. It is critical to do your own research on what you will be planting, what these plants will be in demand of, and what they will leave behind in the soil once you're done with them. A good place to start is understanding different plant families, and the qualities certain crops share with each other.

Cycling out the families


The key to a successful crop rotation is switching out major plant families in different areas each year. This is because each family has similar characteristics of growing needs and oftentimes the same pests attack siblings of the same family. Such as the fungal pathogen blight attacks both tomatoes and potatoes within the Nightshade family. Along with cabbage looper moths and cutworms cause mayhem for the Brassicas family (broccoli, kale, cabbage).

Here are some of the major families and what to expect :

  • Cucurbits (Cucurbitaceae): Squash, cucumbers, zucchini, pumpkins, watermelons, honeymelon, and gourds

  • Pest to expect : Aphids, whiteflies, cucumber beetles, and thrips.

  • Sources : pests for cucumbers , growing needs


  • Brassicas or Mustard (Brassicaceae): Broccoli, cauliflower, cabbage, kale, brussels sprouts, turnips, radishes, mustard greens, collards, arugula, and bok choy

  • Pests to expect : cabbage worms, aphids, cutworms, beetles, and sometimes maggots

  • Source : brassicas growing needs, pests, and more






  • Sunflower (Asteraceae) : endive, lettuce, radicchio

  • Pests to expect : aphids, powdery mildew, nematodes, slugs and snails

  • Sources : Farmers Almanac on Asters




Disclaimer :


There are quite a few sources that claim it is not suggested to plant families of crops together, since they will be more susceptible to pests and drain soil of nutrients. This rings true for families like nightshades, umbellifers, and the brassicas who have a wide variety of pests and pathogens. However, with frequent change of beds and intermingling of companion crops it shouldn't be too detrimental.


I would recommend checking out our Biodivese gardening blog post, to learn more about companion planting. Essentially how certain crops and families may benefit each other from providing soil nutrients, or repelling pests.



Ze Power of Cover Cropping


Cover cropping refers to the practice of planting crops that cover the soil and have beneficial effects in growing, rather than the purpose of harvest (though they can be). Cover crops reduce soil erosion, promote soil fertility and quality, and suppress weeds and pests. Many cover crops are from the Fabaceae family, because of their natural abilities to fixate nitrogen in the soil! Basically meaning beans, peas, vetches, and many other plants are able to accumulate critical nutrients like nitrogen within their leaves and roots.




These are great crops to have during transition periods of seasons, such as sowing or planting these before a major cash crop that will need these nutrients. They can also be used as fertilizer through green manures or distributing the cuttings of cover crops in beds.

  • Cover Cropping :

Any plant cover used to protect and cover the surface of the soil, and prevent soil erosion. The effects of foliage to shield the soil from the “explosive” impact of rain hitting exposed soil, along with the binding and holding power of the roots to prevent erosion. Many domesticated cover crops include legumes (Fabaceae) and annual grasses (Poaceae) ; hay, mulch, and weeds also make effective cover crops.


  • Green Manure :

This refers to a cover crop that is chopped up and turned into the soil. By chopping up the cover crop into small pieces, it increases surface area of biomass and allows faster decomposition by soil microbes. There are two main benefits of this practice :

  1. When incorporated at the pre-flowering stage the crop decomposes quickly and acts mainly as a fertilizer for the “follow up” crop for spring and summer. This approach is more for established soils to fertilize crops.

  2. When incorporated at a more mature stage, like half to full bloom, they have a higher carbon content. This adds even more organic matter to the soil, nutrients are stored and released slowly over a number of years. This approach is more so to build organic matter and improve structure ; build the “body” of the soil.


  • Trap/Catch Crop :

This type of crop functions in effectively trapping or catching nutrients, and preventing them from leaching downward in the soil. For example, Broadleaf mustards and canola tend to take up nitrogen, calcium, and phosphorus. They concentrate them in their leaves, and prevent leaching during rainy seasons. Legumes and taproot crops are also effective in this regard as well.


On this same note, it is important to recognize that alternating heavy and light feeders are vital to cover cropping as well. By switching crops from heavy feeders with light feeders reduces the demands on soil.

  • Heavy feeders include crops like corn, lettuce, broccoli, and tomatoes that use up a lot of nitrogen to produce their fruits and leaves. You can give the beds a rest by planting carrots, potatoes, beets, or onions.


Knowing your Planting Zones !


This is supplemental information to consider what you will be planting depending on your weather in your area ! Mainly because it is important to understand your weather patterns, and what plants would be suitable depending on timing and geography. Here are two kinds of maps that can help categorize your area, and what to expect in terms of weather.

USDA Plant Hardiness Map

  • USDA planting zones

  • Made by the United States Department of Agriculture

  • 11 plant zones for the nation

  • Focused on temperature differences for each zone, highlighting each areas winter lows

  • The higher the zone number is, the warmer the area is

For example, Santa Cruz is a 9B planting zone meaning it has the lowest temperatures of 25-30 F.


Sunset Climate Zones

Considers factors like:

  • Timing and amount of rainfall

  • Summer highs/lows

  • Length of growing season

  • Humidity and Wind

  • Ocean influence

For example, Santa Cruz is a zone 15, with rain from the fall through winter, and has moist air year round because of the ocean.


  • Strategic Planting

It is imperative to understand your area's weather, from when the rain will be expected, frost dates, and overall how your environment will affect your plant babies! Therefore I recommend getting familiar with your area's seasons, to understand what they may mean for your plants, and when you can plant what you like !

I also recommend to journal or keep documentation of what you decide to plant and where, to keep track of what the soil is going through in terms of nutrients and different cycles of plants. There are also many software programs that can do this for you, and easily keep track of your crops and help you plan your beds throughout the year.

Last but not least : The Resources and References


Check out PICA's blog at https://ucscpica.wixsite.com/ucscpica

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