Weeds -- Guardians of the Soil

by Joseph A. Cocannouer

13. Here and Yon

I ONCE received some valuable weed knowledge from a former secretary of state of the first Philippine Republic. The old Don's hacienda, where I first met him, lay very near the land on which we were establishing an experiment station, and he owned some land which we wished to annex to the station. This land was already planted to young coconuts, and was just the thing, we thought, on which to demonstrate the right way of growing coconuts. We Americans out there at that time didn't know much about the right methods of growing this famous palm, but the ex-secretary was considerate of my lack of coconut wisdom, as he was most graciously patient with my limited Spanish.

After the usual bit of courtesy talk with the Don, my native assistant, acting as interpreter, delivered to me the good news that we were to be given the lease on the land for a period of ninety-nine years.

"Fine! " I said, gasping at the ninety-nine-years part. "Thank our generous friend -- now what are his terms?"

Then after a few more minutes of excited palaver -- "The Don say we may have the coconut plantation to do with as we wish, except he ask that we do not cut the weeds that are growing with the palms!"

I really did gasp at that. But after answering for me a barrage of questions which I immediately began hurling at him, the ex-secretary revealed convincingly that he really did know his tropical weeds in their constructive relation to coconuts.

The roots of the palm, he explained, are long and slender and like to feed close to the surface of the ground. He said he had long ago learned that when the roots of the coconut palm are not able to feed very near the soil surface as well as deep in the soil, the trees do not make the growth they should during the earlier years. In the torrid zone, where the rains are extremely heavy, any except a very sandy soil, unless protected by vegetation, is likely to form a thick crust that will not permit the proper functioning of the coconut roots. For that reason, the Don did not like clean coconut plantations. Also, he said he had discovered that the palm roots grew well among the weeds, excepting where the weeds were very, very thick. Years of experience had convinced him that weed roots and coconut roots were not enemies of each other.

It was important to keep the ground clean for a meter or so out from the base of the young trees so the palms could get the necessary ventilation and sunlight, but it would be quite all right to cultivate a strip of land midway between the palm rows. All that the ex-secretary was asking was that we permit the weeds to grow everywhere else.

I accepted the land under the stipulated conditions. But after the old Don had returned to the village and I had sent my assistant about his work, I kept right on sitting there under the mango tree, living over that long-ago talk back there in Sol Benson's cornfield.

Sol Benson and his pusley; the wise old Filipino Don and the weeds in his coconut plantation -- almost the same situation, though ten thousand miles apart. There were all sorts of weeds growing in that young coconut grove: annuals and perennials -- I cannot now recall the name of a single one of them. A matter of minor importance. But it was important that Sol Benson and the Filipino planter had talked to me about weeds in the same manner: what weeds would do when growing with farm crops.

And then I remembered: actually, corn roots and palm roots are very similar in their feeding habits. Sol Benson was certain the corn roots accompanied the weed roots into the lower soils. The palm roots were likely doing the same thing in the coconut plantation. The American farmer and the Filipino hacendero, though many years of time separated them, had each discovered a fundamental weed value: Sol Benson, that weed roots opened the soil so that crop roots could feed deeper; the Don, that unrelated root systems grow better together than when either is growing alone. Each had glimpsed one of Nature's vital laws that govern the soil world.

Some of our own weed friends work well as companion or mother crops, as the Don discovered with his tropical weeds, while others serve best as green manures. There are those that are good divers into stiff subsoils, and those that seem to prefer the loose gravelly subsoils. Then there are those weeds that make particularly good cover for most kinds of land. And the edible weeds: those that make the best livestock forage, and those that are good food weeds in general. Much must still be learned about the whole of weed values before any individual weed can be placed definitely where it will render the best service. Most of our common annuals seem to have several constructive uses. In the discussions that immediately follow, effort has been made to present a bit more information relative to the specific uses for most of our particular weeds, based not only upon my own findings, but also upon the findings of many others who have employed or are now employing these weeds successfully.

I usually think of the pigweed first as a general, all-round weed. There are several species of pigweeds, including the tumbleweed as well as our ornamental coxcomb. They are all annuals and native to America. I am here interested especially in the redroot, coarse-leaf variety, though there is a smooth-leaf strain that is about as good. This weed may be found growing in cultivated fields as well as in waste places. It is deep rooted and an excellent soil improver if correctly managed. Aside from being a first-class mother weed and an excellent green manure, it is a worthy potherb and good for making hay or ensilage. Its scientific name is amaranthus retroflexus.

Lamb's quarter is also a good weed, fitting into about as many niches as the pigweed. It is an annual and a native of Europe. As a general rule, lamb's quarter may be found wherever pigweeds grow, and often as a companion of giant ragweeds. This weed is a good diver and brings up much food material to the surface soil. It is an excellent green manure and makes an ensilage second to none when mixed with legumes. It is also a good mother weed if controlled, and one of the best potherbs of the whole group (chenopodium album).

Then there are the two annual ragweeds, both friends of the land wherever they grow. Both the giant (ambrosia trifida) and common (ambrosia artemissifolia) are native to America. The common ragweed needs no introduction to anyone -- it is almost everywhere. The giant ragweeds, or horseweeds of the middlewest, are a bit more exacting, preferring edges of cultivated fields, open forest areas, or sunny coves where they can grow unmolested. But this weed will also take hold in hard land. It often reaches a height of seven or eight feet where the soil is fertile, and it may be easily recognized by the abundance of pollen which it scatters when in bloom. The common annual ragweed will produce a crop on the poorest of land. Neither of these two valuable weeds is used as human food. The lower animals go for them, though. Cattle seem to eat green ragweeds as a "vitamin"; and quail and other birds relish the seed. Some farmers who have tried it consider ragweed hay excellent forage. The giant ragweed has been used successfully for making ensilage. It is probable that one of the most important uses of the giant rag is to provide seed for many kinds of birds during the winter season, when bird food is scarce.

Our native annual nightshade deserves a high rating. This nightshade may be recognized by its white flowers, which resemble those of the potato, and by its black, berrylike fruit. This is a clean weed and works well for most row crops as a mother. It has a penetrating root system that forages well in the lower soils, and its spreading habit of growth makes it a good soil protector (solanum nigrum).

Then there is the milkweed, shunned by most folks because of the weed's milky sap. I have just read a Johnny-come-lately article recommending milkweeds as superior potherbs; the Indians knew that before the arrival of the white man in America and taught our Colonial ancestors its value. The milkweed is a vigorous-growing perennial, with a root system that wanders far from the base of the mother plant. There are several strains of this weed, each more or less preferring its own soil and location. Rarely is there a field or pasture where a variety is not found. Milkweeds are not soil robbers! I have yet to find a case where these weeds gave even superficial evidence of being harmful to the crop with which they were growing. Most milkweeds will take hold on extremely poor soil if assisted a bit, and do a good job of opening it up (asclepias syriaca).

And now the sow thistle -- which is not a thistle at all; it is a wild lettuce. And it is far from being the noxious weed that some weed books would have it. The sow thistle is a native of Europe and made its way over here very shortly after the Pilgrim fathers. It is now a common weed in gardens and fields and in waste places in most communities. It companions well with most row crops, since the roots feed deep after the plant is once established. The sow thistle will often grow a fine crop of green manure in the fall, a point especially in its favor (sonchus aleraceus).

And the pusleys. The succulent purslane of my boyhood years -- and Sol Benson's cornfield. Purslane is a wonderful soil covering, but not easy to induce to take hold on extremely poor land. It needs fairly good soil to start it off, and that is why most farmers familiar with purslane consider it an out-and-out robber. Once established thinly over a field, the roots of the purslane gather much rich food material in the subsoil and bring this to the surface. And as Sol Benson found, the pusley opens up the ground for the corn roots, or for any other crop with which the weed may be growing. Purslane can be readily recognized by its reddish succulent stems, which lie flat on the ground. It is a native of Europe and an annual (portulaca oleracea).

The other types of spreading weeds differ very materially from purslane. Most of these spreading weeds belong to the spurges, of which there are many. Spurge likes to grow in hard ground, often forming mats in a traveled path. I once made a study of some of this spurge that insisted on growing in the middle of a well-traveled road. It is amazing what the roots of spurge will do to hard soil. I found the soil for several inches out from the weed base to be soft down to a foot or more. Where there were none of these weeds, the soil was stiff, hard clay. On severely eroded land the spurge certainly has a place. It may be hard to get started, owing to the difficulty of collecting and planting the small seed, but once established it will go it alone. The common spotted spurge (euphorbia supina) is a native North American annual.

Here I must introduce a good friend, the annual ground cherry, not because it is a superior soil improver but because it is such a clean weed in either field or garden. There are many strains of ground cherries, a few of which are perennials and consequently do not fit well into the rotation nor grow well as mother crops, as do the annuals. All of these weeds produce their fruit in a sort of capsule. The annual ground cherry, because of its bushy habit of growth, is a good soil shade aside from the value to be derived from its deep-feeding roots -- and its fruits which make the right kind of pies. I have seen these ground cherries taking hold on the poorest kind of land, which indicates their possibilities as conservationists (physalis subglabrata).

And the goldenrod (solidago), good for either gravelly or heavy soils, depending upon the variety. Some goldenrods seem to prefer stiff soils, though as a rule the tribe seems partial to the sandier land. Not long ago I found a piece of very heavy land which the goldenrod was doing a good job of fiberizing. Since goldenrod produces an abundance of seed, it should not be overly difficult to put the weed to work on peeled land or along the brinks of gullies.

Then there is the despicable cocklebur, possessing, like some humans, a few virtues despite its many bad traits. The cocklebur is one of our most persistent native annuals. By including it in this list of perfectly decent weeds, I do not mean that it should be planted on any kind of land. But farmers often have cockleburs in their fields, whether they like it or not. And it is good sense to make use of them constructively. Cockleburs will often do wonders to obstreperous soil if they are thinned enough to permit normal root development. Whenever the plants are scattered thinly throughout the field, cockleburs are not bad companion crops. Many farmers can tell you that corn and cockleburs go it well together (xanthium commune).

The familiar sunflower is a weed whose value to the soil is rarely appreciated. Sunflower value comes not only from the weed's ability to forage well in the deeper soils but also from the fact that the stalks, when broken up and turned under, disintegrate rather quickly. The amount of fiber added to the soil by a heavy crop of sunflowers, not to mention the abundance of plant food which these plants provide, will come near doubling that of any other green-manure crop. The sunflower is an annual and as truly American as the Indian (helianthus).

There are times when a most insignificant weed is able to prove its worth to the soil in a very conspicuous manner. Not long ago I came upon such a case; a case where annual smartweeds (polygonum hydropiper) were doing a good job of draining land. Of course, I had always been familiar with smartweeds. Mother used them to make brine for her pickles -- and kept me on the jump hoeing them out of her Kansas garden. I had long known that this weed also grows where the land is boggy or poorly drained. The patch of smartweeds I refer to here was growing on a strip of very tight land; eroded land that had been crudely terraced and then left to go its own way. Because of the impervious condition of the soil, rain had formed pools back of the ridges, and most of this water remained there until it evaporated. But where the smartweeds had taken over, the smartweed roots fiberized the soil and thus provided for natural drainage. Many farmers have just such conditions scattered through their fields. I mean those low, tight spots where water stands for a long time after a rain. Smartweeds might come to their rescue here if they were to give the weeds a little help. Annual smartweeds are not difficult to eradicate once one is through with them.

And do not forget that the annual wild morning-glory (ipomoea) is not a bindweed (convolvulus), though the two are relatives. The annual morning-glory, another native American, is really not a pernicious weed. While these morning-glories should perhaps not be planted in fields that are regularly cropped, if they move in of their own accord they should be controlled and thus forced to serve as a valuable mother weed. And morning-glories will do a good job on extremely poor land; that is, land that is suffering from a lack of soil fiber. Many farmers know that corn and these morning-glories get along well together.

In addition to the weeds discussed, there are a few others that deserve mention, though they may not be outstandingly beneficial from a soil-building standpoint. One of these is the common wild lettuce (lactuca canadensis), a familiar roadside weed and one which has the ability to penetrate hard soil almost as well as the famous legume, sweet clover. And the shepherd's purse (capsella bursapastoris), a member of the mustard family. The shepherd's purse makes a fairly good winter green manure in some southern sections. Then there is the dandelion. The dandelion may be a pest in the lawn, and in some parts of our country in the field, but in most regions it makes a good mother crop in either the garden or field. In England dandelion is ranked high as a soil-improving weed.

There are many wild legumes, most of which are friends of the soil. These include some of the lupines, the button and burr clover, and the wild vetches and peas found in so many parts. Many of these will grow excellently with non-leguminous weeds, and in the weed-legume combination in land building they surely have a place.

"Yes, but supposing I decide to use weeds in building up some of my poor land -- how do I go about it? This land I'm thinking about is worn out -- dirt plumb gone. Most of it, anyway. Not many weeds on it either -- they won't grow there. Now how am I going to make 'em grow?

When folks start asking those questions, I know they are becoming weed conscious in the right direction. It is true that much of our once-rich farmland is so poor that practically all of our soil-building weeds refuse to make much of a growth on it. In most such situations the weed seeds are there and the seeds germinate, but the seedlings soon die or, because of a lack of nourishment, make little growth during an entire season. They are too weak to reach down into the lower soils.

Here is one place where I heartily approve of the application of some strong stimulant to the land -- to give the weeds a boost during their early stages of growth. By working a small amount of some concentrate (almost any of those now being so highly advertised) into the soil, and then broadcasting the weed seed over the land after the soil is settled well, a good growth of weeds often may be obtained. However, there are situations where even an elixir won't do much in the way of starting the young weeds off. But where it does work, it will keep the weeds going until they have strength enough to forage for themselves.

In planting weeds, a farmer must keep in mind that weeds are very decidedly weeds. Which is to say that their habits are wild. The seed should be scattered over the surface of well-packed or hard ground, not on land that has been freshly plowed. The best time to plant weeds is just before or during a rain in early spring, or in winter when there is snow on the ground. Scatter the seed over the snow and forget about them. While many weeds, such as sunflowers and lamb's quarter, plant easily, some of our best weeds are unpredictable. If they don't grow the first time, you may have to "try again" several times.

Bringing a piece of land back to permanent fertility is probably the most difficult of all farm operations. Too often the farmer fails to make a go of his soil building because he doesn't acquaint himself thoroughly, before starting, with all the adverse factors he is going to have to fight. He gets discouraged because he does not see the size of the job of remaking land that has been weakened for fifty or a hundred years. He has more than likely been schooled to expect the quick response that land makes to stimulants. He forgets that now he is building for permanency, not merely stimulating.

Remember: it takes Nature, working from scratch, from five hundred to a thousand years to build one inch of fertile, perfectly balanced soil. If the land builder would always keep that fact in mind, perhaps he would not want to give up so quickly when he cannot see the slightest progress in his labors. Not, of course, that he will have to struggle for years and years before seeing beneficial results. But to complete a good soil-building job calls for much sweat and time. The valuable work is going on under the surface, but signs of this are often slow in appearing above ground. Only stimulated land, as a rule, will reveal spasmodic responses.

There are really only two vital factors connected with land improvement once the mechanical work has been completed: lime application in practically all cases, and rock phosphate in many of them; and filling the soil with organic materials so that these may be in the soil at all times and at all stages of decay. On very poor land much of the first application of lime is going to be lost, and there isn't much the farmer can do about it. In depleted soils there is no sponge structure. Unless the soil happens to be extremely tight, a very large portion of the lime will be lost through leaching. Yet there must be ample lime at the beginning else not much of a green manure can be expected, especially where legumes are employed. And it is the green manure which must furnish the fiber to rebuild the soil sponge. The green crop also provides the food for the other agents of the soil world that are waiting to move in.

Getting the sponge structure may prove a difficult task, yet rebuilding that sponge structure is very close to the whole of land improvement in the United States today. Not uncommonly, even after two or three excellent crops have been turned into the soil, the land does not reveal any change for the better. At this point in his work it is well for the farmer to pause and try to recall just how long that particu.lar piece of land has been under cultivation. Maybe fifty, maybe a hundred years, and the soil has been deteriorating all of those years! A farmer can in many instances consider himself fortunate if he sees any marked change in such land short of six, eight, even a dozen green-manure crops, although there are often situations where the subsoil is such that it is possible to build a good surface soil from it with only three or four lush crops. Often it may be advisable to give a second and light application of lime after the land starts to show signs of real mellowness. That means there is probably now enough fiber in the soil to hold the lime.

The farmer will generally find that his best bet is to work with mixed green manures. He may have to try out several legumes before he finds the one or ones best suited to his situation. In all events, he should strive to keep a soil-improving crop on the land every growing month of the year. And don't forget that nothing can surpass inoculated legumes companioned with deep-foraging weeds.

Harvesting crops from poor land that is under specific treatment is as a general rule not advisable. Neither should such land be pastured until it is well on its way toward normal productivity. Best to put everything back into the land until normal fertility is restored.

Next: 14. Nature's Togetherness Law

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