|
|
|
|
|
| Coury,Tufi; Malavolta,Eurípedes. |
| The authors discuss in the introduction the literature about the distribution and placemement of fertilizers in agricultural experiments in U.S.A. in such crops as cotton, corn, potato, beans and some vegetables. An experiment was carried out with corn in a randomized block with 7 treatments, and 4 repetitions. The plots were 11,2m wide by 10m long. The 7 treatments were the following: one broadcast, 3 applications of fertilizer in hills and 3 in rows. In the latter six treatments application in rows or hills was combined with applications in three different depths: below the seeds without mixing the soil, below the seeds but with mixing of the soil, and above the seeds without mixing the soil. The variation between treatments was significant, and the best... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1953 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761953000100005 |
| |
|
|
| Coury,Tufi; Ranzani,Guido. |
| The authors studied the action of arsenic, in the form of lead arsenate and sodium arsenite, on cotton in white sandy soil of Piracicaba, State of S. Paulo, Brazil. The experiment was carried out in Mitscherlich pots, applying increasing quantities of the above mentioned compounds. The following conclusions were reached: sodium arsenite is more toxic than lead arsenate. 48 pounds per acre of lead arsenate and 16 pounds per acre of sodium arsenite reduced the vegetative development and the production of cotton. The roots were more seriously affected than the aerial parts. Sandy soils were sensitive to arsenic toxicity. The arsenic mobilization in the soil seems to depend upon factors such as, the a- cidity, the concentration of Fe2O3, CaO, P2O5 and soil... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1945 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761945000100012 |
| |
|
| |
|
|
| Coury,Tufi; Ranzani,Guido. |
| The authors carried out a series of pots and plots experiments applying arsenical and organic insecticides to cotton plants cultivated in "terra roxa" and in a sandy soil. The first results were presented in 1947, to the la. Reunião Brasileira de Ciência do Solo (First Brazilian Congress of Soil Science); they pointed out the danger resulting from the accumulation of arsenic in soils due to the constant applications of arsenicais to control cotton pests; in the course of the time, the amount of residual arsenic in the soil would determine a decrease in cotton yield caused by its toxic effect on the crop. The following conclusions were drawn from the last three experiments: 1) the field experiment conducted in a sandy soil to which lead arseniate was... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1953 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761953000100003 |
| |
|
|
|
