SOME THOUGHTS ON COVER CROPS AND THEIR ROLE IN AGRICULTURE

 

SOME THOUGHTS ON

COVER CROPS

AND THEIR ROLE IN AGRICULTURE

RICHARD FINDLAY

 

We read about, ozone depletion, global warming, soil erosion, inflation and water is a diminishing resource, scary stuff!

 

What can us as farmers do about it? There are three routes we can choose to follow to answer that question, each with its own action, its own outcome, the choice is yours.

 

  1. We can elect to do nothing and stay in what we think is our comfort zone.
  2. We can look at using No-Till to address these problems which it does to a large extent
  3. We can combine No-Till with using cover crops to enhance what we are already doing.

 

As we are talking to the converted mainly through our new letter we all know the benefits of No-Till but some have not thought of combing it with a cover crop to maybe compound the effects of No-Till.

 

Coming from the seed industry my interest in cover crops was probably a selfish one to begin with, as it was extra seed that I could sell and therefore enlarge my market share, but as I found out more about cover crops it became evident that this practice could have greater benefits to the farmers themselves than to my inflated seed budget.

 

To share some of the benefits of cover cropping I am going to use some facts obtained from an American hand book on cover crops called MANAGING COVER CROPS PROFITABLY. Printed by The Sustainable Agriculture Network.

 

SOME OF THE FARMERS ARE ALREADY USING COVER CROPS:

 

Winter wheatis also a cover crop used by farmers with irrigation following a summer crop of maize and this has financial benefits if grown properly and you obtain a reasonable yield.

 

My main interest is to encourage those farmers who are dry land maize farmers to look at using a hardy cover crop that would, conserve moisture, control wind erosion and possibly create grazing to market animals off the farm. There is also the possibility of producing seed for some seed company, who often battle to get suitable ground on which to produce good seed on fields that are not contaminated. Examples are cereal crops like stooling rye, triticale, oats and even annual ryegrass.

 

BENEFITS OF COVER CROPS:

 

You cannot help becoming excited with the prospect of trying cover cropping when you have read the build up this book gives you, but like all new concepts and fancy ideas you need to, stop, and se how it fits in with your farming practices and personality before heading into some writers fantancy.

 

When you looks at what cover crops can possibly do for your farm and ultimately your finances from detail obtained from this book and others as well a personal communication with practicing agriculturalists one must consider the merits carefully.

 

These are some of the benefits mentioned:

 

Ø       Cut fertilizer costs by using legumes for nitrogen and root crops that re-cycle P and K. It is mentioned that Grazing Vetch in Maryland from a 3 year study was worth 80kg of Nitrogen per ha.

 

Ø       Reduce the need for herbicides and pesticides by smothering the weeds and in the case of insects allowing areas for the friendly (the useful ones) insects to over winter. This is used in the fruit industry, they tell me that there are insects that over winter that control many insects that cause damage to the fruit.

 

Ø       They also improve your soil structure enhancing soil health by in creasing humus and carbon content. Soil with a good structure and humus content also has a filtration effect on herbicides and pesticides that may be still lurking around.

 

Ø       Limit soil erosion due to the fact that the soil is covered slowing the rate at which the water from a heavy rain storm leaves the field, keeping the soil where it belongs.

 

Ø       As the rain water is slowed up by the vegetation on the surface of the field you give the water time to sink into the soils and not run off and into the river. The root systems of pervious crops and cover crops that have decayed in the soil that has not been ploughed to also assist the water to penetrate, increasing the moisture retaining characteristics of the soil.

 

Ø       With water being control on the field and not allowed to run wild gathering all sorts of soil particles in its haste to get into the river. Your surface water will become cleaner and improve in its quality for humans and animals alike.

 

These benefits should be sufficient to make you want to consider using cover crops around you rotational crops you are growing so let us look at some important questions you need to ask yourself in order to make an intelligent decision.

 

The following is a list taken from this handbook:

 

Refer to your timetable chart and ask these questions:

 

·                     How will I seed the cover crop?

·                     What’s the weather likely to be at that time?

·                     What will soil temperature and moisture conditions be like?

·                     How vigorous will other crops or pests be?

·                     Should the cover crop be low-growing and spreading, or tall and             vigorous?

·                     What weather extremes and field traffic must it tolerate?

·                     Will it winter kill in my area?

·                     Should it winter kill to meet my goals?

·                     What kind of re-growth can I expect?

·                     How do I kill it and then plant into it?

·                     Will I have time to make this work?

·                     What is my contingency plan—and risks—if the crop does not establish or it does not die as scheduled?

·                     Do I have the needed equipment and labour?

 

This gives you some idea of what is required before jumping into using a cover crop. It will cost you money to plant it and it needs to work for you and create the benefits you have foremost in your mind to improve soils.

Here is some detail I came across in MANAGING COVER CROPS PROFITABLY and have taken the liberty include it here for you to read.

 

Cover crops can stabilize your soil:

 

The more you use cover crops, the better your soil tilth, research continues to show. One reasons that cover crops, especially legumes, encourage populations of beneficial fungi and other micro-organisiums that help bind soil aggregates.

The fungi called mycorrhizae, produce a water-insoluble protein known as glomalin which catches and glues together particles of organic matter, plant cells, bacteria and other fungi, recent research suggests. ( Wright. S.F and A Upadhaya 1998 (372)

Glomalin may be one of the most important substances in promoting and stabilizing soil aggregates.

Most plant roots, not just those of cover crops, develop beneficial my-corrhizal relationships. The fungi send out root-like extensions called hyphae, which take up water and soil nutrients to help feed plants. In low-phosphorous soils, for example, the hyphae can increase the amount of phosphorous that plants obtain. In return, the fungi receive energy in the form of sugars that plants produce in their leaves and send down to the roots.

Growing cover crops increases the abundance of mycorrhizal spores. Legumes in particular can contribute to mycorrhizal diversity and abundance, because their roots tend to develop large populations of these beneficial fungi.

By having their own mycorrhizal fungi and by promoting mycorrhizal relationships in subsequent crops, cover crops therefore can play a key role in improving soil tilth. The overall increase in glomalin production also could help explain why cover crops can improve water infiltration into soil and enhance storage of water and soil nutrients, even when there has been no detectable increase in the amount of soil organic matter.

That has given you food for thought which I hope will lead to you pursuing cover crops to feed your soil!

 

There is a long list of species and cultivars within those species that can be use as cover crops and we will include these in our next edition. Should you want more detail immediately contact the writer through our secretary.

 

NEWS FROM THE COMMITTEE:

 

Egon Zunckel was elected as chairman at our committee meeting in October last year and Andrew Lawrens s now vice chairman.

 

HOPE TOWN FARMERS VISIT BERGVILLE:

There was a bus full of farmers from the Northern Province who visited Egon’s farm on the 2nd November. Unfortunately it was an extremely wet day, the bus got stuck in the mud and Egon had to clear a space in his workshop to accommodate the 30 plus farmers in the group. The weather was damp and wet but the enthusiasuim of the farmers to here about No-Till was hot. Both Egon and Anthony spoke of their experiences.

 

By Richard Findlay