ABSTRACT Direct seeded canola (Brassica napus L.) has become increasingly popular in China’s key canola-producing regions. The studies on the K response of direct-seeded canola performance are limited. This research aimed to investigate the K utilization efficiency and canopy radiation interception rate of direct seeded winter canola at various K application rates. Two seasons field trials were done with five K levels (0, 75, 150, 225, and 300 kg K2O ha-1) utilizing two key local cultivars (Huayouza no. 9 and Zhongshuang no. 11) in Southwest China. Canola yield rose by 17.9%-82.6% in 2017-2018 and 21.1%-73.6% in 2018-2019 when K was applied, compared to K-unfertilized. Canola yield go up rapidly at first and then gradually when K ingestion grew, demonstrating the phenomena of K luxury consumption. As K levels rose, internal utilization efficiency, agronomic efficiency, and physiological efficiency all decreased. In canola pod development and maturation period, 150 kg K2O ha-1 intercepted the most solar radiation (73.8%), while K-unfertilized treatment intercepted the least (61.6%) on average. The K supply rates had a significant effect on canopy radiation interception and K absorption in winter canola. When K application exceeded a specific rate, luxury consumption occurred. Canola’s luxury K consumption was mostly stored in the pericarp and plant stem.

Neste trabalho, grafeno foi usado na extração em fase sólida dispersiva de 11 herbicidas triazina e 5 inseticidas neonicotina da água. As condições de extração como quantidade de grafeno, solvente de dessorção e pH da solução foram otimizados. Nas condições otimizadas, um enriquecimento de alta eficiência foi alcançado na análise quantitativa dos pesticidas. Triazinas e neonicotinas foram determinadas por espectrometria de massas-cromatografia gasosa (GC-MS) e cromatografia líquida de alta eficiência acoplada à espectrometria de massas (LC-MS/MS), respectivamente. Os resultados indicaram que o grafeno foi um excelente adsorvente na adsorção de pesticidas. A recuperação dos pesticidas foi 83,0-108,9% com desvio padrão relativo (RSD) entre 2,4% e 12,3%. Os limites de detecção (LODs) variaram entre 0,03 μg L-1 e 0,40 μg L-1. Finalmente, o método proposto foi aplicado na análise de amostras reais, como água de torneira e de rio.

In this work, graphene was used for dispersive solid-phase extraction of 11 triazine herbicides and 5 neonicotine insecticides from water. The extraction conditions such as the amount of graphene, the desorption solvent and the solution pH were optimized. Under the optimal conditions, high efficient enrichment was achieved for the quantitative analysis of the pesticides. Triazines and neonicotines were determined by gas chromatograph-mass spectrometer (GC-MS) and high performance liquid chromatography electrospray tandem mass spectrometry (LC-MS/MS), respectively. The results indicated that graphene was an excellent adsorbent for the adsorption of pesticides. The recoveries of the pesticides were 83.0-108.9% with relative standard deviation (RSD) between 2.4% and 12.3%. The limits of detection (LODs) ranged from 0.03 μg L-1 to 0.40 μg L-1. Finally, the proposed method was applied for real sample analysis, such as tap and river water.