Show heavy crops drain soil of plant food mineral supply needed to restore fertility heavy wartime crop droppings pings drained wice twice as much nitrogen from illinois soils soil as was put back by fertilizer OPP applications locations licati ons or legume crops declares 0 L whalan university ol of illinois what was true in illinois was tru true of farm soils in numerous other M midwestern dw estern states approximately tons ot of rill nitrogen tro en were removed from the soil in harvested crops in the 1942 46 period whalin whalan points out but only about tons ol of nitrogen were returned to the land this replacement included nitrogen in fertilizer applications plus 60 per cent of the nitrogen in legumes harvested und end in sweet clover turned under the supply of other mineral elements was seriously depleted whalin estimates that only about half of the phosphorus taken from the soil was replaced less than one thirtieth M leth as much potash was added through commercial fertilizers as was removed by harvested crops this heavy drain on the soils mineral supply says whalin has reached the point where crop yields on many soils definitely depend on the amount of minerals applied manure inoculated legumes phosphate and potash are required will maintain and even increase yields on most a soils 1 I carrying out such a program he be adds calls tor for use of lime on much k I 1 rich west virginia mountain lime plant lime Is sold t 0 the farmers to increase production on crop and pasture land of the land nin order to grow leg unies lime should be applied on the basis of soil tests it should be used from six months to a yeah before legumes are seeded in order to sweeten the SOIL deep rooted legumes deep rooted legumes work in two major ways to improve rebuild soil structure and increase the supply of 0 mineralized organic matter well fed legumes such as sweet 1 clover or alfalfa push their taproots deep into the soil these roots TIGHT SOILS CUT YIELDS NO LEGUMES LEGUME IN OVATION 00 TATION A CO 0 ED W icom lo 10 ian ZO TS 2 5 60 open up tightly packed earth below the plow furrows neither water nor air can penetrate such compacted soil crop roots cannot do da their job of carrying nutrients to to the plant growth factory abiva abo ground but when deep rooted legumes are grown frequently in the rotation and soil structure are improved the land becomes loose and easy to work channels channe I 1 s for air end and water and passageways eways for the roots ot of following crops are made deep rooted legumes are em 2 j cl dent ent fedders on the soils available a Is phosphorus and potash they can faragi tor for these plant foods when jtb othir r crops will tail fall th tha legumes gather these nutrients into int their taproots when plowed under these roots put all important mineralized erali zed organic matter down where it should be readily available for the roots of other crops following in the rotation soil rumi fumigant gant stops work of nematodes in its war on toll soil pests scientific fic research has forged a fatal n new wa weapon an against nematodes the worms whose burrowing activities cau cause se nearly two million aclei ot of farmland a in tin the south to lay idle every year this weapon is III so soil 11 fumigant known as DD D D whose chief component is pans pane and its use allows allow repeated plantings planting year after year of kanj man crops which now are rotated |