Cater to Cows’ Tastes by Soil Treatments on Pastures

While we are emphasizing the use of more grass as cover for the soil against erosion, we are subconsciously including more cows as the means of converting that herbage into human food values. It is, of course, high time to practice more conservation of the soil, but is also necessary to design any enlarged program of grass production so that it will cater to the cows’ tastes as well as cover Nature’s nakedness.

It was Prof. R. J. Pool of Nebraska who pointed out that “Nature is not a nudist by choice, but man has robbed her of the means by which she can grow cover for her modesty.” That remark suggests that crop removal and no return of fertility bring on its depletion and expose bare soils which would otherwise be naturally covered quickly. It might also suggest that soils too poor to grow their cover quickly are growing a vegetation that is probably too poor in quality to serve as animal feed.

During any campaign for more grass it is fitting to ask the question whether we are catering to the cow’s tastes when thin, infertile, eroding lands are put to grass of any kind merely for the sake of cover. Shall we not emphasize the function of the grass as feed for the cow more than as blanket protection against falling rain-drops and as miniature dams against water running in rivulets? Isn’t the production of highly nutritious forage the primary function of putting land into pasture; and isn’t the saving of the soil the secondary one when by proper soil treatments the primary function can be carried out and the secondary one can be accomplished simultaneously without extra cost?

When Pastures “Run Out”

Whenever a part of the farm has some topographic features to make the use of larger machinery difficult, or if its productivity is making economically questionable the yields of seed crops under tillage, we are prone to consider putting it down to grass. If a fairly respectable sward results in the early years of such a program, it is usually not very long before the pasture is “taken by the weeds” or considered to have “run out.”

When such conditions result, we are inclined to search for some new grass crop that will give tonnage production again where the bluegrass or preceding combination of pasture plants could no longer survive. When weeds take over the pasture, we often consider mowing as a good help to restore grass by eliminating the weeds as competitors for soil moisture along about mid-summer.

That the cow’s taste enters into this weed problem in pastures because the declining soil fertility gives lowered feed quality in the pasture crops may, at first thought, seem far-fetched. But what is a weed in the pasture, after all? Isn’t it a kind of plant which the cow will not eat? Should we not think of it as one that can make only woody bulk refused by the cow because the soil isn’t fertile enough to grow the more nutritious herbage which the cow takes regularly. In Nature it is the forests or woody crops that occupy the soils which are thinnest and not so productive when cleared and put under cultivation. Can’t we believe that the cow is allowing the weeds to grow because they are not producing anything worthy of her consumption for its nutritive value? If she refuses to mow the weeds, her seeming fastidious taste is telling us that our running the steel mowing machine over the pasture is not striking at the crux of the problem of getting good grass as she judges it.

More soil fertility where six tons of manure were applied annually on continuous corn (upper photo) grew winter protection against erosion, while no soil fertility returned to the companion plot left the soil naked (lower photo). Condition in early May, Sanborn Field, Columbia, Mo. Photo Missouri Agricultural Experiment Station.

 

When pastures go to weeds, nature is merely adjusting the crops by bringing in those that can make their growth on less of the soilborne nutrients that are essential for animals and plants. Weeds are made more extensively of air and water which are fuels rather than real nutrition. The mowing machine cues down the plants the cow refuses to eat. But it adds no new supplies of lime, phosphorus, nitrogen, potassium or other essential elements that would encourage the dominance of plants like blue grass and legumes using these soilborne nutrients in manufacturing the higher feed values the cow prefers as she demonstrates in her preferential grazings. Pasture renovation calls for other machines in addition to the mower. It calls for the manure spreader or the lime and fertilizer distributors, as the cow’s taste tells us.

Catering to the Cow’s Tastes Guides Soil Building Wisely

The grazing animals have so often demonstrated their discriminating tastes that most any farmer can report startling observations of the choice by cattle between forages according to differences in the fertility of the soils growing them. Usually the animal takes, first, in the humid regions, the forage where the soil was limed, given phosphate, manured or made more fertile in some way. Observations of such were reported by E. M. Poirot of Golden City, Mo., when his beef cattle grazed first the small parts of the barley field where in drilling out the corners he doubled over and thereby applied 200 pounds of mixed fertilizer in contrast to only the 100 pounds put on the rest of the field.

Choices by the cow and other animals are apparently not so often the cases where only one nutrient element is applied. They are probably more often cases of the better balance of several elements through which the feed output by the crop fits better into the animal physiology that is registering its needs by way of the animal’s discriminating taste. Almost everyone is familiar with pasture scenes where there are bunches of the tall green grass resulting from the nitrogen dropped there in urine from the livestock. The cow disregards these bunches to let them grow taller while she eats the short grass around them still shorter. That the cow recognizes the lower feeding value of grass with this excessive and unbalanced fertilizer treatment, is suggested by the failure of experimental rabbits to do well when fed grass similarly fertilized, while their litter mates did well on the same species of grass not fertilized with liberal amounts of this one element alone.

When the shelled grains of corn from a series of plots producing different amounts of sweet clover turned under as nitrogenous green manure ahead of this crop were put into separate compartments of the self-feeder for hogs, the animals exercised an interesting selection. With 100 pounds of grain in each compartment representing one particular plot of the series, fertilized to give more clover growth turned under, the relative rate of com consumption was measured. This consumption rate decreased as the extra soil treatments gave greater amounts of sweet clover turned under as green manure. The corn from the plot with no soil treatment and therefore little sweet clover turned under was most highly preferred. However, when red clover was the green manure, their relative selections were reversed. Their consumption rate was highest where soil treatments gave the largest amounts of this green manure turned under. These differences demonstrate variable responses by the animals’ taste according to the nature of the nitrogenous fertilizer turned under for the corn. Seemingly one is a balance and the other an unbalance for them.

Here are the suggestions that plants grown on the better soils in terms of general balance of fertility are chosen by animals because of greater nutritional service from them. When plants as forages, or even their seeds, are not taken by animals, there is the suggestion that the soil is of low or of unbalanced fertility from which the vegetative growth cannot compound those substances of most nourishing services. Catering to the cow’s taste by treating the soils to grow grass crops according to her likes may be a kind of soil building under the guidance of a highly refined animal assay rather than under that of the laboratory chemist. Taking the cow’s tastes into consideration would seemingly lead us to a better pastoral agriculture, when the measure of it is taken in terms of meat and milk.

Fertile Soils Immune to Weeds

We have not yet come generally to believe that by feeding lime and other fertilizers into our soils we make them healthy soil bodies to the same degree as we believe for our own bodies the old adage “that to be well fed is to be healthy.” Yet, when it is almost axiomatic that there is much immunity to infectious disease in our good health, might we not consider that good health of soil through fertility may represent in it an immunity to invasion or “infection” by weeds? For if soils are well-stocked with all the necessary elements of fertility, they will encourage rapid growth of dense cover of the planted, desirable grasses with which weeds cannot compete. On such soils the fertility diet for the crop is one that encourages the plants which are given to synthesizing the complex compounds of highly nutritional value and thereby those that satisfy the supposed idiosyncrasies of the cow’s tastes. Does this not suggest that an insufficient soil fertility, or poor diet, for crops gives weeds and thereby a poor diet for the cow in terms of her choice and her output of food products for us?

Cattle grazed out the barley first where in turning around with the grain drill the regular application rate of fertilizer was doubled. Photo by E. M. Poirot, Golden City, Mo.

 

Sanborn Field, with its 55 years of cropping history at the Missouri Experiment Station, recently demonstrated the fact that high fertility in the soil may well be considered an immunity to weeds, while soil exhaustion may be manifested by an increasing susceptibility. Two plots in this old field have been in timothy continuously since the start of the field in 1888. One is given six tons of manure annually. The adjoining plot gets no return of any fertility. Both have hay taken off every year.

While the timothy under regular manure treatment grows well and excludes the weeds, the plot with no manure starts off with a good stand after each occasional reseeding following plowing. But it is gradually taken by weeds. Consequently, it demands plowing and reseeding of both plots about every 6-8 years in the attempt to keep them more nearly comparable as timothy stands.

This shift during about 6 years from timothy to weeds in this plot which is cropped continuously but given no return of fertility or no manure, suggests a greater susceptibility to weed infestation. This was demonstrated forcefully by the advent of broom sedge (Andropogon virginicus) a few years ago when this plot was approaching the eighth year following the last plowing and reseeding. The weedy hay crop of a ton and a quarter taken in June was followed by a broom sedge crop of 3200 pounds per acre in late October. These combined annual weed productions were a tonnage yield greater than that of fine timothy hay in July on the adjoining manured plot. Yet had the cow been permitted to exercise her choice she would have classified the latter crop of lesser tonnage as good feed and the former of greater acre yield as weeds and not as feed.

Broom sedge took over one of the two plots in timothy continuously where no manure was used (right), but did not infest the adjoining one given manure annually (left). (Lower photos were taken before the feathery seed heads had ripened.) Photo Missouri Agricultural Experiment Station.

 

Only this one plot amongst the 40 or more plots with all the different fertility treatments on this experiment field had become susceptible to an infestation by broom sedge. Can we say that the winged seeds that started this weed crop were dropped on this plot alone and not over the borderlines that separate it from the plots adjoining? Can we imagine that the light feathery seeds of the “Old Man’s Beard,” as this weed is often called, were not scattered over the entire field at the same time they were seeded on this plot?

Here is encouragement to believe that infestation by weeds may be viewed as a case of our neglect of the fertility of the soil rather than the visitation of a great evil upon us. The applications of manure, lime, and other fertilizers may well be considered as a prevention of weeds at the same time that they are helps in providing more and better animal feeds.

Consider the Cow While Considering the Crop

Unfortunately, the tonnage yield per acre has been the prominent criterion that has guided our search for, and selection of, forage and grass crops. When one crop has gone down in its yields we have brought in other crops, mainly because they gave more pounds or tons per acre. Such has been the story of the introduction of some forage legumes, originally quite foreign. Consideration has not gone to the crop’s capacity to cater to the cow whose taste is concerned and whose service as a provider of milk or meat as well as a regular multiplier of her own kind are at stake. She is, after all, the final criterion that must come in to determine what services will be rendered by the crop that must be consumed by her and thereby converted into human food products.

The grass crop is good mechanical help against erosion in terms of its services as soil cover. But as a cover it cannot be laid on the land except as the fertility of the soil grows it there. This same soil fertility determines how serviceable grass will be as a feed for the cow that converts it into cash. It is primarily this latter function for which grass is grown. It is essential, thereby, that the applications of soil fertility for growing more grass as soil cover be guided toward making better feed of it by catering to the cow’s taste through soil treatments. For the dairy cow there may well be considered the same philosophy of feeding as was suggested for the hog by Professor J. M. Evvard when he said, “If you will give the pig a chance, he will make a hog of himself in less time than you will.” The cow, too, may classify under this category if we cater to her tastes.