Show manure straw needed by soil careful return of manure Is an all aid to land that needs potash by L B miller Mso associate clate in soil experiment fields university of iiii nois service i careful return of manure and straw to fields pro provides V ides a soil security pt program for those lands ithac ithac a are re on the verge of a potash deficiency in the growing lof of corn land fand grain crops fully two thirds of the potash content is in the cornstalk and straw if these byproducts by products farm are left on the land lor or are applied as manure they return some potash to the soil bank V to be used again A study of crop yield data over a 20 year period on six soil expert i mental farms on the gray soils shows that yield levels were as high with manure as with potash basic treatments of limestone and phosphate having been used in each each lease case the manure was applied at ithe ithe rate at which with careful management a it could be accumulated on any live stock farm for the farmer who markets his crops as grain the problem is some what different at one soil experiment field the corn yields on limed gray silt loam on tight clay for the rotation ending in 1928 1923 were 28 bushels since that time yields have declined to 21 bushels this decline appears to be caused by potash deficiency for with the application of oats straw at the rate of two tons an acre for each four byear year rotation ion since 1929 the corn have been revived to an av jerage of 45 bushes bushels for the last ilour year period this treatment seems also to have satisfied the needs of other crops in the I 1 rotation analysis of the straw showed that each two ton application contained about as much tysium as is supplied by pounds of of potash after limestone and clovers have boosted crop yields above levels farmers will do well ato watch for potash deficiency not that legume farming is a breeder of potash shortage in the soil but as yields go up greater demands are made upon soil minerals when crop growth is sufficient to exhaust the supply of any one of the plant nutrients trien ts the crop is handicapped A minimum acreage of soil de pl eting cultivated crops such as corn and soy beans together with the return of manure and straw will go a long way toward making farms self sufficient in their potash requirements quire ments |