Assessing the evaluation methods of nutrient effect at different growth stages of maize

It was imperative to research the mechanisms of nutrient effect at different growth stages so as to enhance plant nutrient assimilation efficiency. In this study, field experiments considering sowing date, density and fertilizer dose were conducted to evaluate this process in "Nonghua 101" maize cultivar. Daily mean temperature was recorded and leaf and other fractions sampled during maize growth period for chemical analysis and N, P and K concentrations. While population effect was introduced into the analysis on the basis of daily dry matter accumulation, thermo temperature effect was introduced in terms of environmental conditions. Then the Best Linear Unbiased Prediction (BLUP) method was used to assess the evaluation methods of nutrient processes and efficiency during maize growth stages. Next, the accuracy of the adopted method was determined from main statistic parameters using the SAS software. Based on the results, the correlation coefficient (r) between expected daily dry matter accumulation and observed data was 0.72~0.99. Paired T-test analysis showed that the trends of the different growth stages were insignificant at P > 0.05. The variance between observed daily mean dry matter accumulation and expected value was also insignificant at P > 0.05. It was then obvious that the main parameters of effects of nutrients at different growth stages varied remarkably. The ranges of nutrient effect values of three leaf to jointing stage, jointing to flare opening stage, flare opening to silking stage, and silking to maturity stage were 0~0.58, 0.43~2.57, 0.45~4.58 and 0.86~4.71, respectively. The modified BLUP method was therefore potentially suitable for evaluating the effects of nutrients at different maize growth stages. The method was therefore recommended for field evaluation of the effects of nutrients on maize production.