Welcome to Book of the Week – a weekly feature offering you a glimpse between the pages of an Acres U.S.A. published title. Get the Book of the Week email newsletter delivered directly to your in box! This week’s Book of the Week feature is Albrecht on Pastures, by William Albrecht.

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 cows’ 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 cows’ 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, Missouri. (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 cuts down the plants the cow refuses to eat. But it adds no new sup- plies 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 Cows’ 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 corn 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.

About the Author:

Dr. William A. Albrecht, the author of these papers, was chairman of the Department of Soils at the University of Missouri College of Agriculture, where he had been a member of the staff for 43 years. He held four degrees, A.B., B.S. in Agriculture, M.S. and Ph.D., from the University of Illinois. During a vivid and crowded career, he traveled widely and studied soils in the United States, Great Britain, on the European continent, and in Australia.