THE REAL RUTGERS RESEARCH

Experimental Work

Samples of cabbage, lettuce, snap beans, spinach, and tomatoes were obtained from commercial fields of these crops in Georgia, South Carolina, Virginia,Maryland, New Jersey, New York (Long Island), Ohio, Indiana, Illinois,and Colorado. The samples were collected by Dr. Dana G. Coe, whose careful selection of them constituted a highly important part of this work. The total number of samples examined was 204.

The collecting had to be done during the midsummer months, and this made it impossible to obtain samples of all five crops from all 10 states. Fortunately,samples of snap beans and tomatoes were taken from every state. This report,therefore, deals primarily with the findings on these two crops. Bountiful snap beans and Rutgers tomatoes were chosen for collecting, and most of the samples belonged to these two varieties. So far as possible, the cabbages,lettuce, and spinach samples were confined to the Golden Acre, Grand Rapids,and Savoy varieties respectively.

All samples were collected at the stage of growth when they were being harvested for market. Field collection was followed by as rapid transportation to the laboratory as possible. Only the edible portions were prepared for analysis, the outer leaves of cabbage and lettuce being discarded. All samples were rinsed in cold distilled water. The tomatoes were rubbed also with a clean cloth. The samples were dried in a hot-air convection oven at temperatures ranging between 70-80 deg C. Samples of the vegetables were wet-ashed with a mixture of nitric and perchloric acids and made up to volume. Aliquoes were then analyzed for the major nutrient elements by standard procedures, including the use of the flame photometer for determining Ca, K, and Na. Another sample was dry-ashed at between 600-700 deg. C and analyzed form the minor mineral nutrient elements by the use of a spectrograph.(Spectrographic analyses were made by Dr. Harry S. Reed to whom the authors are very much indebted.)

Characteristics of soils on which vegetables were grown

The soils involved in the eastern coastal-plain states were of the Tifton,Bladen, Orangeburg, Portsmouth, Norfolk, and Sassafras series. These belong to the podzolic group, including both the red-yellow and the gray-brown zones. They have all been developed from coastal-plain materials and have been thoroughly leached. They have relatively low exchange capacities,and they contain only very limited supplies of mineral nutrients.

The soils involved in the east north-central states were of the Wooster, Miami, Crosby, Brookston, Clarion, and Webster series. The first four are members belonging to the gray-brown podzolic group, which have been developed on glacial drift, some of which was of a calcareous nature. Those of the last two series are prairie soils, which have been developed from calcareous glacial drift.

The Colorado vegetables were obtained from areas where the Laurel, Gilchrist,Berthan series predominate. These soils belong to the brown and planosol groups, and are under irrigation farming. They are high in calcium carbonate and in available mineral nutrients.

Fertilizer practices in the areas involved

As Beeson has pointed out (4), fertilizing and liming practices influence the mineral composition of plants. Consequently, it seemed desirable to make a survey of these practices as employed on the fields from which the samples were selected. The data from this survey are summarized in Table 1. It is important to note the relatively high rates at which fertilizer is applied in the coastal-plain states as compared to the rates employed farther west. In the east north-central states less dependence is placed on fertilizers and greater use is made of clover sods and manures. Only relatively small amounts of fertilizer are used in Colorado.

The rate of use of lime increases from Georgia northward to New Jersey. It varies considerably from farm to farm in the east north-central states. No lime was used on the Colorado farms.