Cultivating Questions Annual Cover Crops versus Longterm Sod
Cultivating Questions Annual Cover Crops versus Longterm Sod

Cultivating Questions

Concerning the Bioextensive Market Garden

by Anne and Eric Nordell of Trout Run, PA

Annual Cover Crops versus a Longterm Sod

We must confess we feel guilty.

Reviewing the past six years of this column we realize we have sometimes taken up almost half of The Journal trying to answer the shortest of questions. In this installment of Cultivating Questions we intend to mend our verbo-extensive ways by beginning with a long and involved question from Paul Conway of Leavenworth, Kansas and then limiting ourselves to a “relatively” short answer. We share both of Paul’s epistles here because they summarize so well all the aspects of a whole farm approach to sustainable soil fertility.

Dear Anne and Eric,

What follows below is the first of two letters that I will send you concerning soil quality and sustainable practices. As I organized my thoughts, I found that I could not cram all I wanted to write into one letter. This first letter will cover some general principles (for want of a better term), ridge tillage, no till and its consequences for sustainable/organic, and several cover crops that I use more frequently now in my rotations. The second letter will cover the heart of sustainable farming; what rotation type is adequate, comparing long-term forage legume based rotations with shorter ones to answer the question “how much soil building is enough?”

I tend to think in sequential steps so I often try to extract “principles” as a foundation or guidance for what I do. A statement of a goal helps. To make sustainable farming profitable and ecologically sound requires work toward an integrated farm “system” where crops (rotations), animals, manure and inputs (if any) support and complement each other. This system makes best use of the renewable resources generated by the farm itself. Your farm is an example. This is probably the work of a lifetime; the farmer makes continual adjustments as he gains experience. You have to start with a basic plan which is difficult unless you have done some research.

I came up with these principles/tenets/foundations/pillars (you pick a word) commandments (if you want a catch phrase) to make this goal achievable.

These are:

1. Rotations Matter: Good diverse rotations are the heart of sustainable agriculture, it is the first and most critical step to a profitable and ecologically sound farm system. There is no cookie cutter ideal rotation, which is probably why implementing a good rotation is so difficult for most farmers. In this area, farmers often decide what to plant based on last year’s commodity prices. This is probably the worst rationale for rotations.

2. Pay Attention to Organic Matter in Soils: Active organic matter in soil is the catalyst that turns minerals, soil particles, etc…into productive soil. Organic matter is more important than minerals since low organic matter results in the soil microorganisms being less active; so minerals are less available. Obviously, minerals, both major (P,K) and minor are important. On this subject, there seems to be so many theories on what makes soil productive that I think soil science is a misnomer. Unfortunately, many theories seem to be an article of faith among most organic farmers. I am not sure that cation exchange, element balancing and minor/ micro-nutrients are that important. I do use gypsum on crops that need a lot of calcium and my soil tests are based on the Albrechtian concepts, so I am not completely skeptical. I am still trialling this. So far, I believe that you should make sure that your soils contain enough P and K, and the pH is adequate to grow clovers/alfalfa. Green manure plowdown plus animal manures with some inputs, if needed, takes care of the N and all of the rest. If in doubt, conduct test strips for several years to get a good baseline for changes.

3. Manure and Compost are Important to Build Organic Matter: Use manure if you have access to it. Manure complements cover crops/green manures and makes forage based rotations better. Either green manures or animal manures can replace each other in the short term but farmers should use both for the best resuls. It is possible to oversupply manure, but it is relatively easy to prevent this. Grass type cover crops such as rye, sorghumsudan, can trap excessive N, prevent leaching while improving soil tilth, and absorb P if levels are too high.

4. Judicious Tillage is a Practical Goal: As you mentioned in your article, “The Politics of Tillage,” agribusiness is beating the drum of no-till as the only answer to soil degradation. Some tillage is necessary, excessive tillage coupled with poor rotations and excessive salt fertilizer applications, destroys soil microorganisms and organic matter. The trick is to do just enough tillage to do a specific job (turning under a legume sod, etc…) at the right time. Organic farmers should always think through how and when they do tillage if only to protect themselves against the chemical industry and agribusiness propaganda.

Ridge Till: I have always been interested in the results of your ridge-tilling methods. In my case, wet soil in the spring can delay planting of early vegetables. I always till up some strips as part of the rotation for early spring crops. This year, in early October, I disked in oat seed for a winterkill cover crop and used my 2-row lister cultivator to make ridges (disk hillers turned in). I will plant onions on these ridges. I hope that this method will enable me to plant early crops in heavier soils. 10154 onions are particularly susceptible to neck rot. I would rather use sorghum-sudan but it was too dry in September to plant this forage on the ridges.

No-Till: No-till can be a useful method to combat soil degradation and improve organic matter but it is not the “magic bullet” cure-all as agribusiness hype suggests. It is an engineering approach to solving a biological problem using mechanical means. It’s an oversimplified solution. In this area, no-tillers follow the same poor corn-soybean rotation with little if any use of cover crops and continued use of anhydrous ammonia. The result is a layer of residue over concrete hard soil. I grant you that no-till can be a great tool when combined with good rotations, use of cover crops, etc… I would rather compare no-till with conventional, and then with good sustainable/organic operations before reaching any conclusions. On the same soil types as well. A farm where cover crops, manures and good rotations produce a biologically active soil, in effect, actually sequester carbon. I would think that working under a good green manure or forage legume stand would produce enough soil biological activity to balance the destructive effects of tillage. Again, use the right tool and do only what tillage you need to. By the way, cultivation is not the same as tillage in my mind.

5. Cover Crops: There is no single silver bullet cover crop, each crop has its own particular niche in a rotation scheme. The following are ones that I am using more because they fit in well with my rotations. I still use the old standbys, i.e. hairy vetch plus forage legumes in my various rotations:

a. Grasses, such as rye, sorghum-sudan, oats. I have access to lots of horse manure. Legumes don’t seem to nodule much in my soils as a result. So I now use the grasses to suck up N from manure applications, plus the large biomass produced by these crops add to organic matter, suppress weeds, etc… Sorghum-sudan is especially valuable as it is drought tolerant, fast growing and winterkills readily. Its roots are massive. Sorghum-sudan produces a crumbly, mellow soil much like buckwheat. It plows beautifully.

b. Oats. Not all straw rots the same. I have noticed that oat straw decomposes faster than wheat straw which is the standard straw here. Straw is good for mulches and as an ingredient for compost. Oats grow well with various red clovers and sweet clover. The oats might make the clovers fix more N. Mown “mature” oats and clovers form a rapidly rotting minimulch; some years it feels like walking on sponges. A clover/oat mix or sweet clover/oat may be the best choice here for a soil builder in short rotations. Sweet clover can grow to a height of 1 – 1 ½’ by June from a March sowing here.

c. Forage Soybeans. Soybeans are an excellent Nfixing green manure. Public varieties, especially non- GMO types, are getting harder to find. Why pay more for a private variety for plowdown? The forage types, while somewhat pricier than standard public ones, are taller, leafier and less daylight sensitive. This is good because I often plant soybeans after early July. They are also an excellent grazing crop for temporary pastures. Forage soybeans are also readily available. Cowpeas stand drought better here, but are less universally adapted than soybeans and more expensive. Not so, 100 miles South of here.

In the next letter, I will talk in more detail how green manures fit into developing my rotations.

Regards, Paul Conway

Cultivating Questions Annual Cover Crops versus Longterm Sod
From “Fertility Management at Roxbury Farm” by Jean-Paul Courtens.

Dear Anne and Eric,

This is the second letter of the two I promised you. I trust you received the first. In this letter I will discuss my thoughts on rotations. I am still undecided about which rotation would be the most practical and profitable balance between soil-building crops and cash crops. The more I think about it the more questions arise. Of course, there will never be an ideal or “one size fits all” rotation. But there should be some general principles that we all should follow.

We all know that tillage eats up organic matter and the microorganisms that make soil fertile. Sustainable farming rests on the concept that rotations between soil-building and “soil destroying” crops creates a balance that limits the negative effects of tillage. But what rotation is best? Conventional wisdom has it that long rotations based on several years of forage legumes or legume/ grass mixtures followed by cash crops are the least destructive to soil organic matter. Is this really true? Can a shorter rotation be an adequate substitute? Can heavy applications of manure/compost along with Winter/Summer cover crops also sustain organic matter?

In my case, most of my fields are in an 8-year rotation, 4 years of alfalfa followed by 4 years of vegetables. I apply manure or compost and use cover crops in the vegetable cycle. Most of my fields are gently sloping. I must stripcrop along the contour to control erosion. Legume strips alternate with vegetable strips; natural water paths are in permanent grass with short growing legumes. Some strips are heavy clay which made establishment of alfalfa difficult. Other strips and one separate field are in a shorter rotation with 1-2 years in legumes forages then 2-3 years of crops again with manure and cover crops included in the vegetable phase. One field is in continuous vegetables all on raised beds. I use heavy compost applications here, short duration cover crops and seeding some beds to NZ white clover every year for a one/two year “fallow.”

The ability in our climate to double or even triple crop vegetables complicates the rotation question. Vegetables can exhaust soil quickly, double cropping should speed this up. Heavy compost applications may not counteract this soil degradation adequately, you can also over apply compost. So which rotation can best counteract this effect?

I hired an organic consultant to help me think through this problem. He recommended the long rotation plan that I implemented above. I was supposed to use the mowed alfalfa as a N sidedressing worked in between the crop rows. This proved to be wildly impractical unless I bought more machinery and hired more labor. I can barely keep the alfalfa mowed in wet years, I can save some of the alfalfa as compost material and I do use a good bit for mulching and some for hay. I really don’t need much hay. It would be a different story if I had cattle, hogs or any other economic livestock. As an aside comment, this proves that you should never hire a consultant unless you already have a good idea of what you are doing; this was a man whose judgement I still trust but he advised a practice that was impractical for my operation.

Alfalfa seems to be the key ingredient to long rotations. Longevity, deep tap roots for drought tolerance, allopathic tendencies and good N fixation makes alfalfa an excellent forage legume where it can be grown. It may require uneconomical amounts of time to work well in very acidic thin soils. What I thought was a 30% stand on some heavy clay ground due to grass competition turned out to be a 60% stand when the dry Summer stunted the grass. Alfalfa, however, does not compete well with Johnsongrass, nor does it tolerate even occasional wet soil. I had to plow one alfalfa strip and then plant buckwheat followed by sorghum-sudan in ’02 in an attempt to suppress Johnsongrass. I will replant alfalfa with oats here in 2003 and see what happens.

My chief problem is that alfalfa is hard to establish without a drill. In both 2000 and 2001 I broadcast and harrowed in April alfalfa into standing winter wheat (more consultant advice). Without fail, the wind kicks up in Kansas whenever you broadcast seed or spread rowcover – uneven pattern. The weather was either too dry or too wet or the wheat was too tall. Establishing alfalfa in clay ground was especially difficult. I did end up with somewhat acceptable stands with some bad spots where the Johnsongrass and the alfalfa coexist. A thinner wheat stand may have helped. Most farmers here try to establish pure alfalfa stands in Aug-mid Sept; in wet years this works well. I also could sow alfalfa in the Spring with some oats into winterkilled oats or sudan for winter erosion protection, maybe I could mix in some red clover as insurance to handle wet spots since red clover is usually easy to establish here. Would an alfalfa/grass mix, say 70/30 or 80/20% alfalfa to grass, promote more microphobial activity and better organic matter production than straight alfalfa?

I cannot pass judgement yet because I have not completed the alfalfa cycle. I will have a better picture after plowdown if the advantages of alfalfa outweigh the planting problems and its high seed cost. I don’t even want to think about the price of “organic” alfalfa seed. I have seen good crop yields and weed control after three years (seeding year plus two) of alfalfa on one strip.

Cultivating Questions Annual Cover Crops versus Longterm Sod

Can a long rotation be established without including alfalfa? Clovers, both red, white (NZ white is especially suited here) and sweet clover are easy to start here. Frost seeding starting in mid-February works well here unless the grass sod is too rank or we have a very dry Spring. Red clover isn’t particularly drought tolerant but does have a good root structure and can fix a lot of N given moisture. Sweet clover has the advantage of deep taproots but its hard seed survives forever if the plant sets seed. Sweet clover sets seed in late May the year following Spring planting, Fall planted sweet clovers flowers the next Spring here. I am starting to wonder if this really is a bad thing. Why couldn’t sweet clover reestablish itself the third year? Furthermore, I should be able to control seedlings by cultivation if I decide to follow two years of sweet clover or sweet clover mix with crops.

Another option for lengthening a rotation is the use of grasses. I have noticed that legumes do not always nodule well in my soils. Planting an aggressive grass such as winter rye or sorghum-sudan might deplete available N in the soil while their heavy growth and massive root systems build organic matter and suppress weeds. The following forage legume, which could be left for 2-3 years, will be forced to set nodules; plus winter-killed sudans make a very friable seed bed after providing lots of erosion preventing residue over the Winter. These grasses also provide a good window for heavy applications of “raw” manure with the full benefits of the manure coming into effect the second year.

This may also solve my problem with legume stands on clayey ground. Could massive applications of fresh or composted manure followed by a grass crop such as sorghum-sudan make the clay more friable? I could follow up with sweet clover frost seeded the following year then Fall plowed for a year or two of suitable crops. So I may need a separate rotation model for my clay ground. In the meantime, I will disk up the alfalfa stands on clay soil to roughen up the soil so that clovers have a change to establish.

I do know that I don’t want a very short rotation on my sloping ground as this would make me do too much tillage.

Double-cropping really complicates the issue. Ideally the ability to double crop most vegetables where irrigation is feasible would more than offset any loss of income from the forage strips. What appeals to me most, however, is the ability to concentrate labor and inputs on a smaller portion of my land while nature improves the soil on the rest. But all this intensive concentrated tillage is going to severely degrade the soil in these strips. Lots of compost and short-term cover crops will help but the soil will need a rest period. Is a one year legume fallow enough? Is a 2-4 year break better, as I think it is?

No matter what rotation model or models I eventually choose, short-term cover crops will stay in the cycle. Their flexibility and complementary relationship with manure makes them useful in addition to their traditional values. Even undersowing works here with some crops; the trick is to seed the legume then till out strips for the cash crop.

To conclude, I have no answers yet. My gut tells me legumes or legume grass mixes are necessary in a rotation for at least two years. A legume grain mix may be better than a straight legume stand and cover crops keep the soil biology active and pump in N. Again, there will never be an ideal universal rotation. I really have no idea how this will turn out. I hope that KSU decides to help me by measuring soil organic matter levels as it would be nice to have some numbers.

Sometimes I think that I am leaping over mouse droppings and this is not a subject of much importance.

I would value your thoughts. I always enjoy your articles because they make me think.

Sincerely, Paul Conway

Cultivating Questions Annual Cover Crops versus Longterm Sod


Without a doubt, a long-term sod is the most sustainable way to improve soil quality. In fact, a perennial grass-legume crop may be the only way to substantially improve the humus levels and soil structure of farm soils without importing organic matter in the form of manure, compost or mulches.

We think there are at least two distinct reasons that a long-term sod can improve soil quality without additions of off-farm organic matter. First, the constant growth and dying off of a large perennial root system adds organic matter to the soil on a continuous basis. Secondly, the combination of permanent ground cover and undisturbed soil protects this slow-but-steady accumulation of humus from oxidation. No wonder that perennial grass-legumes mixes have played an essential role in traditional farm systems.

To be truthful, we have not been able to reproduce the superior soil structure produced by a long-term sod using our fallow year system of annual cover crops and light applications of compost. However, there are several reasons why we stick with rotational cover cropping in the bio-extensive market garden rather than relying on semi-permanent covers to maintain good growing conditions for vegetable production.

From a practical standpoint, most of the crops in our market mix do not appreciate being planted right after a long-term sod. For example, the coarse seedbed and active fermentation resulting from the plowdown of a grasslegume mix is not always desirable for direct-seeded market crops or delicate transplants. In our area, the buildup of grubs, slugs and wireworms under a perennial sod is also a deterrent to using this traditional soil building component in our rotation plan.

(Using a bare fallow period, or an annual cover crop, between plowing down the long-term sod and planting the first cash crop may solve all of these problems. So would developing markets for crops, like sweet corn and fall brassicas, that really thrive after the incorporation of a semi-permanent grasslegume mix. Another solution would be to introduce field crops, such as corn or soybeans, into the market garden rotation to ease the transition between sod and vegetables.)

In terms of weed control, we have often noticed that perennial weeds dispersed by the wind, e.g. dandelions, can become problematic in long-term cover crops. The same holds true for low growing weeds that cannot be controlled by mowing, or rhizomonous weeds that creep into the field on their root systems. So the decision to use a long-term soil building sod in the market garden rotation may partly hinge on the nature of the weeds growing on the farm.

On a more controversial note, we are not convinced that a long-term sod builds the kind of organic matter that holds up the best in a cultivated system. The reason we dare say this is that when we brought the old hayfields on our farm into vegetable production, organic matter levels dropped dramatically within a couple of seasons of cultivation. Although it has taken years to rebuild soil organic matter to the original hayfield levels using our fallow year cover cropping system, these levels seem to be holding their own despite a good bit of seasonal variation.

(According to Will Brinton of Woods End Lab, the duration of the “sod effect” will vary from region to region depending on soil type and climate. For instance, his research showed that yield increases and soil improvement resulting from a long-term sod lasted for 2-3 years in Maine, but only 1 year in Pennsylvania.)

While this may seem like heresy to suggest that annual cover cropping combined with small applications of compost may produce more durable organic matter than using a semi-permanent sod, we have talked with experienced vegetable growers who have noticed the same thing – the organic matter produced by a long-term sod seems to disappear relatively quickly after planting vegetable crops while the humus developed by the regular use of annual cover crops and compost seems to hold up longer under constant cultivation.

The opposite, however, is the case regarding soil structure. At least, in our experience, the crumb structure produced by annual cover crops is not near as long lasting as the soil aggregation produced by the massive root system of a semi-permanent sod.

We think the placement of organic matter in the soil profile should also figure into the comparison between annual and perennial cover cropping systems. As the accompanying chart from Jean-Paul Courtens’ manual on “Fertility Management at Roxbury Farm” indicates, almost half the organic matter produced by an annual cover crop is contained in the above ground biomass. Annual cover crops make a lot of sense in our moisture preservation system because we can work all that coarse organic matter into the surface of the soil, creating a mulch to absorb and retain rainfall.

By contrast, the bulk of the organic matter in a long-term sod is found in its huge root system underground. Therefore, a perennial grass-legume mix has the potential to develop the humus and crumb structure much more deeply in the soil than a system based entirely on annual cover crops. Like Paul Conway suggests, probably the best way to maintain all aspects of soil quality would be to include both perennial and annual cover crops in the market garden rotation.

In recent years, we have tried to realize some of the soil building advantages of a long-term sod, while minimizing the drawbacks, by planting short term sod crops in the fallow year before heavy feeding LATE crops, like storage potatoes. The photo essay details our 2001 trial using June planted Italian ryegrass and clover.

Unfortunately, the following crop of “grass-fed” potatoes did not produce very well due to the extremely hot weather and high insect pressure in 2002. On the plus side, we did not see any of the disadvantages we usually associate with growing potatoes after a long-term sod, like wireworm damage.

We put together the accompanying outlines on Weed Control and Alternative Tillage to make it easier to see how grass-fed potatoes fit into the overall market garden rotation. The Alternative Tillage Techniques outline looks at the decision making process we used for all of the cover crop-tillage combinations we now use on the farm. The rotation charts in the outline on Weed Control illustrate how these cover crop-tillage combinations work together to create two new variations on our original four year rotation scheme.

Keep in mind, that the bio-extensive market garden is comprised of twelve half-acre fields so it is not unusual to have several variations on the original four-year rotation taking place at the same time. In this way, we can utilize all the cover crop-tillage combinations in the market garden each year.

If the soils in our production area ranged from well-drained sand to heavy clay, then we would need to develop distinctly different crop rotations and cover crop-tillage combinations tailored to the requirements of each soil type. Which leads to Paul’s important question about determining the best rotation and soil management practices for the clay soils on the steeper parts of his farm.

We have contacted a couple of growers who have a lot more experience with sloping clay soils, hoping that they will be able to contribute to this topic in the next CQ column. We also hope to tackle the slug control challenge mentioned in the last issue. If you have thoughts about either of these topics, please write them down and send them our way so we can include them in our “short answer” in the Summer 2003 SFJ.

THE PROBLEM: A major soil building component of our original four-year rotation was overseeding EARLY cash crops with yellow blossom sweet clover. During the following fallow year, we clipped the clover a couple of times before plowing it down to begin the midsummer bare fallow period. Usually the second clipping of clover occurred around the 4th of July when the sweet clover was in full bloom as shown in this photo taken way back in 1991.

Mowing the fallow field of flowering clover destroyed the habitat for a whole host of good and bad bugs, forcing them to move into the adjacent cash crops, like the midsummer plantings of lettuce, flowering kale, tomatoes, peppers, zucchini, etc…you see to the left. This cover crop management strategy turned out to be problematic in the mid-90’s as the flowering clover attracted a growing population of tarnished plant bugs. When we mowed the sweet clover in full bloom, we unwittingly moved the TPB’s into the nearby rows of midsummer lettuce where they cause a good bit of cosmetic damage.

THE ANSWER: 1. Shift the growing window for clover so that it did not blossom – or require mowing – during the summer months when the tarnished plant bug is active. 2. Create a full season insectiary effect in the market garden with successive interseedings of blossoming buckwheat to provide a more tempting habitat for the remaining TPB’s than our mainstay cash crop of lettuce.

(Note: Alfalfa is also a host for the tarnished plant bug. Mowing the alfalfa in staggered strips may maintain sufficient habitat for the TPB’s so that they won’t move en masse into nearby fields of lettuce or other susceptible crops. Tarnished plant bugs are probably best known for the damage they cause to strawberries, causing small, deformed fruit when they chew on the young buds and blossoms.)

Adapting the Cover Crop Rotation to Changes in Insect Pressure

Tarnished plant bugs were not a problem when we developed the original four-year rotation for the market garden in the early ‘80’s. By the beginning of the 1990’s, this pest had set up housekeeping in our area, blemishing our midsummer plantings of lettuce.

It took us a few years to realize that we were aggravating the problem by growing clover in the fallow year sequence preparing for LATE planted cash crops. Apparently, the TPB’s were attracted to this flowering legume because when we mowed the clover in full bloom we saw a lot more tarnished plant bug damage in adjacent plantings of lettuce a few weeks later. Removing the TPB’s preferred habitat and food source all at once seemed to encourage this voracious insect to move into the nearby cash crops.

When we finally made the connection between mowing the blossoming clover and the increase in TPB damage in the lettuce next door, we decided to delay mowing the clover until all of the nearby lettuce had been harvested. At the same time, we began interseeding our successive plantings of short term cash crops, like lettuce, spinach and peas, with a single row of buckwheat as described in the Spring 1999 column on Dealing With Crop Residues.

The idea was to create a full-season insectiary effect in the market garden with the successive interseedings of blossoming buckwheat, in this way, moderating the boom-and-bust cycle of both good and bad insects. Specifically, we hoped that the interseedings of buckwheat would provide an alternate host for the TPB’s when the clover finally had to be mowed. This strategy seemed to be pretty effective. In fact, the NEON researcher tracking four plantings of lettuce in 2002 (see the Winter issue for more background on the NEON project), found very little tarnished plant bug damage in our lettuce but lots of these bugs in the insectiary interplantings of buckwheat.

Shifting the growing window from clover has also been a contributing factor to the dramatic reduction in TPB damage in our lettuce in recent years. Instead of overseeding clover into the EARLY cash crops and mowing it midsummer during the following fallow year when it was in full bloom, we began planting the clover in June of the fallow year as illustrated in Variation #1 of the four-year rotation in the Weed Control outline. This simple change in the cover crop rotation delayed the clover from blossoming until the end of the growing season when the tarnished plant bugs were no longer hungry and active. In this way, we could still utilize clover in the market garden rotation without it serving as a magnet for all the TPB’s in the region. At the same time, this shift in the growing window for clover meant we did not have to mow it when the adjacent plantings of midsummer lettuce were growing.

Establishing the clover cover crop in June of the fallow year still provided plenty of time for this leguminous sod to produce a significant, soil building root system the year before LATE planted cash crops. To enhance the soil structuring potential of this short-term sod, we have been experimenting with mixing italian ryegrass in with the clover in recent years. We found that their aggressive, complementary root systems could form a pretty substantial sod between seeding in June and the ground freezing up.

Fortunately, the italian ryegrass is not a host for the tarnished plant bug. Unfortunately, we have noticed that it does attract a lot of leafhoppers. If ryegrass is mowed in June or July, the leafhoppers have a tendency of moving into a nearby crop of potatoes and causing a good bit of damage. The beauty of using the biennial italian ryegrass variety is it does not go to seed during its first year of growth and consequently does not need to be mowed to prevent it from becoming a weed. By planting the italian ryegrass and clover combination in June of the fallow year we can take advantage of their soil improving properties without increasing insect pressure in the nearby cash crops.