Reduction of soil nitrates during the growth of soybeans
1928
Deatrick, E.P.
It is concluded that nitrates in soils under maturing soybeans are very low. When the soybean harvest is so late that the period between the harvest and the planting of the wheat is too short to allow for considerable nitrification, the supply of nitrates is apparently too low to produce an increase in the yield above normal. The decrease in nitrates is thought to be largely due to absorption by the plant. Where it is desired to follow soybeans with winter wheat in a rotation, it appears advisable to plant soybeans of shorter growing periods so as to allow for longer intervals for nitrification in the soil before the planting of the wheat. The results of the pot work indicate that a long period for nitrification is more beneficial than top dressings of 200 pounds of nitrate of soda or 8 tons of manure per acre, regardless of whether the soybean tops are removed or not.
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