Effect Of Rainfall On Phosphorus Leaching In Maize Conopy

Nutrient leaching of plant Canopy is the current research hot point at home and abroad, and it is also the foreland in the study of plant ecology, plant physiology and plant nutriology study currently and in the future. Xing-yu998(X), Yu-yu22(Y), and Zhong-dan5384 (Z) were chosen as the test materials in this paper, a pot and artificial rainfall methods were used to validate whether rainfall could leach phosphorus in the corn canopy. The changing characters of canopy phosphorus leaching were studied on different periods of rainfall and corn at different growth stages to explore the effect of soil phosphorus and plant phosphorus nutrient levels on phosphorus leaching effects of corn canopy. Main results of research are as follows:1. With the growth period advanced in the period of studying, the phosphorus leaching amount of per leaf area in the corn canopy reduced gradually in each leaching period, the highest was in the jointing stage and the filling stage was low. This shows that the change of leaching amount beared upon the growth period. In the jointing stage, the mean phosphorus leaching quantity of per leaf area was 0.382μg/cm2 and the filling stage was 0.031μg/cm2,while the flowering period and maturity period was 0.175μg/cm2,0.034μg/cm2,respectively. Overall, with each rainfall leaching time extension, the phosphorus leaching amount of per leaf area on corn canopy reduced gradually, the leaching amount changes had an inverse relationship with the time, the differences of different growth stages were in basic agreement.2.The phosphorus leaching amount of the corn canopy had a significant positive correlation with the stomatal frequency in the upper and lower epidermi(sP<0.05), this shows that the more stomata per unit area of maize leaf, the more the phosphorus leaching amount. The phosphorus leaching amount on the corn canopy had a significant negative correlation with the stomatal area in the upper and lower epidermis and the stomatal perimeter (P <0.05), the bigger the stomotal area and the longer the stomotal perimeter, the more the phosphorus leaching amount.3.There was a significant positive correlation between the phosphorus leaching amount of the corn canopy and the Pn, stomatal conductivity and transpiration(P<0.05).This showed that the higher the Pn, the bigger the stomotal conductivity and the higher the transpiration, the more the phosphorus leaching amount. There was no significant correlations between phosphorus leaching amount of the corn canopy and the intercellular CO2 concentration in leaf and the relative content of leaf chlorophyll(SPAD).4.The phosphorus leaching amount of the corn canopy had a significant positive relationship with the size of leaf apparent free space(AFS):Y=0.3203X+0.1314(R2=0.60). The above correlation analysis showed further details, as the leaf area, stomotal frequency, and the gas exchange capacity between leaves and the environment increasing, the phosphorus leaching amount on the corn canopy showed a general increasing trend.