ChileanJAR

Nitrogen and phosphorus are two of the most important nutrients to obtain a good yield with wheat in "trumao" soils.
It was studied the effects of nitrogen and phosphorus on yields and the content of both nutrients in a winter wheat variety, Cappelle Desprez, in a "trumao" soil.
The effects of both nutrients were analized with a multiple regression analysis using the second grade polynomial model.
A lineal correlation analysis was also used.
The regression analysis showed: a positive lineal effect of nitrogen and no effect of phosphorus upon protein percentage of grains; a negative quadratic effect of nitrogen; a positive lineal and quadratic effect of nitrogen; a positive lineal and quadratic effect of phosphorus, and a positive effect of interactions upon phosphorus percentage of grains; a positive lineal of nitrogen and positive quadratic of phosphorus upon nitrogen pereentage of straw; positive lineal effects of both nutrients of phosphorus upon yield; positive lineal effects of both nutrients upon protein productions per given area, and a positive lineal effect of phosphorus and a negative quadratic effect of nitrogen upon extracts of phosphorus from grains.