bers of pest insects and thereby benefit crops. On the other hand, the roses generally are known to harbor aphids. Will the net change between good and bad insects be beneficial or harmful? The experiment station in Maine is starting observations on the potato aphid in relation to multiflora rose. Fragments of evidence are turning up here and there mostly indicating an improved position with respect to insect damage-but much more factual information is needed.

The shrub lespedezas, notably Lespedeza bicolor, are proving of great value in providing proper land use and erosion control on field borders and other areas in the Eastern States as far north as southern Pennsylvania and south through Georgia, west to the semiarid region. Their use by wildlife, especially the bobwhite quail, has been outstanding. There are twenty-odd species of these woody lespedezas known, all from the Orient. Some species other than bicolor have been and are being tested. Strains of bicolor are being found that promise to be superior to the run-of-the-mill plants. For example, a selection labeled "101" appears to produce far more seed than average, and to hold the seed on the plant longer into the winter where it is available for wildlife food., However, its use is restricted to the zone where killing frosts do not frequently occur before October 15. Another strain of bicolor called Natob matures its seed a week or two earlier than average, hence can be used successfully farther north than the common plant. Further testing of species and strains should provide superior plants for soil conservation and wildlife habitat.

There is a general need for improving the pollination of crop plants that depend upon insects for cross-pollination. It is well known that some prevalent exploitive farming practices reduce the numbers of pollinating insects. The bulldozing out of shrub farm boundaries-the only woody cover available-in the Ukraine when the Russians were obliterating the old land-ownership pattern and organizing the collective farms some years ago resulted in buckwheat crop failures due to lack of pollination. This extreme case illustrates the dependence of many of our crops upon certain kinds of insects. We believe that a good soil-conservation program, particularly the inclusion of appropriate biology practices, increases the numbers of beneficial insects needed for pollination. Some of the citatious above substantiate this belief. Much more adequate and specific information is needed on this relationship of conservation practices to pollinating and other insects and yields of crops.

The relationship of marsh-water levels and control to marsh-plant composition and distribution and, in turn, to fur yields, is a field needing much study. Some demonstrations in the East and South have indicated some of the methods that may be used to increase yields from marshes. These techniques include dikes, dams, and tide gates to control general water levels; level ditching to improve the distribution of open water; and prescribed burning. The relationship of mosquito control to marsh management for wildlife is a very important matter in areas of high human populations.

Studies need to be undertaken to learn more about the effect of specific soilconservation practices on wild animals. For example, does the use of mulches in clean-tilled peach orchards to control erosion increase damage to orchard trees from field mice which might live under the mulch? We do not know much about the relations of insect numbers to such conservation practices. Prairie crawfish in Mississippi and Alabama fields that damage crops present a problem although their numbers were reduced recently through a technique of applying DDT. These and other types of damage to crops from wild creatures require compensatory measures, some of which are not yet adequately understood.

Increased attention must be given to the relationship between wild animalsinsects, fish, birds, and mammals—and land use if we are to fully understand how soil- and water-conservation operations affect wild creatures and are in turn affected by them. Wildlife has a material influence upon soil conservation, and soil conservation means a very great deal to American wildlife.

STATISTICAL SUPPLEMENT

As a statistical supplement to the narrative report above, and to provide a means of comparing progress with that previously reported to congressional committees, there are presented the following tables, together with four maps showing the growth of soil-conservation districts in the United States as of December 15, 1938, December 15, 1941, December 15, 1944, and December 31, 1947.

TABLE 1.-Growth of conservation districts by 6-month periods

1 Includes 1,940 soil-conservation districts and 23 other conservation districts.

TABLE 2.-Number of farm conservation plans and acres, prepared with Soil Conservation Service assistance in districts, fiscal years (cumulative) 1

1 Most of the conservation farm plans in previous programs administeed by the Soil Conservation Service, like the demonstration projects, the CCC erosion camps, and others, are now included in soil-conservation districts. Many of the old cooperative agreements with farmers have now been converted to farmer-district agreements.

TABLE 3.—Major soil and water conservation practices, farm and ranch plans, as of Dec. 31, 1947