Maize Yields and Soil Nutrient Levels With and Without Pesticides and Standard Commercial Fertilizers
1980
Lockeretz, William | Shearer, Georgia | Sweeney, Susan | Kuepper, George | Wanner, Diane | Kohl, Daniel H.
Because of increases in the price of chemical inputs to agriculture, uncertain supplies, and environmental concerns, a reduction in pesticide and fertilizer use may become increasingly desirable, if it could be achieved without a major reduction in output. For this reason, it is of interest to compare yields obtained under present conventional practice with those obtained at the lower limit of chemical intensiveness. This paper reports maize (Zea mays L.) yields on two groups each of 26 commercial mixed grain and livestock farms covering a wide range of soil types in the western Corn Belt. One group was managed with conventional fertilization and pest control practices, while no herbicides, insecticides, or standard commercial fertilizers were used on the other. The mean yield from the convenional fields was 8.5% higher than from the matched fields on which conventional fertilizers or pesticides were not used. The difference was not statistically significant (P<90%). Conventional maize yields tended to be higher than maize yields on fields which received no pesticides or fertilizers under favorable growing conditions and lower when conditions were adverse. Grain from the fields receiving pesticides and fertilizers had a significantly higher crude protein content. These fields also had a significantly higher incidence of Diplodia stalk rot and lodging. Soils from fields receiving no pesticides and fertilizers had a significantly higher (P>95%) organic C content, as well as higher total N (P>90%), but lower Pt phosphorus (P>90%). Differences in P2 phosphorus, exchangeable K, C:N ratio, CEC, and pH were not significant (P<90%)
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