Sufen Sun

Chemical fertilizer plays an irreplaceable role in raising vegetable output and improving the livelihood of people in China. Chinese cabbage (Brassica chinensis L.) is one of the most common vegetables with a wide planting area. However, there are problems such as the excessive and blind application of chemical fertilizers, which bring about the increase of planting cost and the risk of environmental pollution. So, it is urgent to improve fertilization methods and improve fertilizer use efficiency, aiming to promote the sustainable development of agriculture. In this study, multi-year and multi-site experiments were retrieved from the published literature and public scientific research institutions to study a sustainable fertilizer recommendation method for Chinese cabbage based on yield response and agronomic efficiency. The results showed that the average indigenous nutrients supply of nitrogen (N), phosphorus (P), and potassium (K) were 112.98, 35.03, and 213.15 kg/ha, respectively. It is suggested that these nutrients should not be neglected in the process of fertilizer recommendation. The average yield responses to N, P₂O₅, and K₂O were 26.6, 13.9, and 16.6 t/ha, the relative yields were 0.70, 0.84, and 0.84; also, it was concluded that the agronomic efficiencies were 114.3, 108.5, and 89.4 kg/kg on average, respectively. From these datasets, the theoretical basis of recommended fertilization was established. It was found that there was a significant negative correlation between N, P, and K indigenous nutrient supply and the yield response to N, P₂O₅, and K₂O, and a significant negative linear correlation between yield response and the relative yield of N, P₂O₅, and K₂O. There was also a significant one-dimensional quadratic function relationship between yield response and agronomic efficiency in Chinese cabbage. Then, two years of field experiments for Chinese cabbage were conducted to verify the fertilizer recommendation. It was concluded that fertilizer recommendation for Chinese cabbage based on yield response and agronomic efficiency was a sustainable way for farmland utilization, not only economically and suitably satisfying its application on fields of different sizes, but also taking into account the indigenous nutrient supply and the interaction between N, P, and K, having shown the advantages of high efficiency, especially when the conditions such as soil testing and plant diagnosis were not sufficient.

To explore the effective method of the pepper diseases, using the method of combining the genetic algorithm and BP neural network, the establish neural network diagnostic model for pepper diseases is established to improve the model convergence rate and accuracy. The experimental results show that the model is convergent effectively and the diagnostic accuracy is improved by 12%.

The international research trend of tomato molecular breeding was studied based on thesis analysis in SCIE. Through the analysis of the annual number of articles, reveals the variation trend of related research. By the analysis of Scientific productivity and achievement influence, compares the research competitiveness among countries. Use the co-word clustering to identify 6 important research topics in the field, and use the strategy coordinates to evaluation the relative position of these topics .The result shows that, tomato molecular breeding research presents a rising trend. The United States plays an absolute leading role in the field. China’s research layouts more but achievements influence is relatively low. # 5 (tomato genome) and # 1 (resistance) themes are the center of tomatoes molecular breeding. # 2 (oxidative stress) may be the center of the future research.