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Weichanglu, China

Zhu Y.-G.,Shandong Agricultural University | Zhu Y.-G.,Shandong Academy of Agricultural Sciences | Li H.-J.,Shandong Academy of Agricultural Sciences | Cui X.-Y.,Lingcheng District Bureau of Agriculture and Forestry | And 5 more authors.
Chinese Journal of Applied Ecology | Year: 2015

To study the farmland eco-environment of intercropping maize with wheat at the intercropping stage and its influence on maize seedling growth, two summer maize cultivars, Zhengdan 958 and Denghai 661, were either intercropped with wheat or directly seeded. The result demonstrated that there was little difference for the soil water content of the farmland between the two cultivation methods. The highest soil temperature of intercropped maize was 4.8-5.2℃ lower than the soil temperature of directly-seeded maize, and the lowest temperature of the intercropped maize was 1.4-1.7℃ lower. But, the temperatures for both planting methods met the requirement for seed germination. Light intensity on the ground surface of the intercropped maize was 4.4%-10.6% less than natural light, and insufficient light was the main reason for the weak and late seedling. Compared to the directly-seeded maize, the speeds of seed germination and accumulation of dry matters of the intercropped maize were relatively slow. On the whole, the seedling of intercropped maize was not strong, which presented small leaves, short height and low chlorophyll content. The restraint on the growth of intercropped maize was enhanced with the extension of intercropping period. For farm planting, direct-seeding could improve the seed germination and seedling growth of summer maize. ©, 2015, Editorial Board of Chinese Journal of Applied Ecology. All right reserved.

Hao M.-B.,Shandong Agricultural University | Wang K.-J.,Shandong Agricultural University | Dong S.-T.,Shandong Agricultural University | Zhang J.-W.,Shandong Agricultural University | And 4 more authors.
Chinese Journal of Applied Ecology | Year: 2010

According to the maize yield at plant density of 15000 ind . hm -2 in 2007, the leaf-redundant type (cultivar Chaoshi 1) and non-redundant type (cultivar Chaoshi 3) at low plant density were selected, and the changes of their above-ground dry matter accumulation and grain yield after cutting all leaves to 1/2 (T 1) and 1/4 (T 2) at anthesis at the optimal density and under high-yielding condition were analyzed in 2008, aimed to approach whether the leaf redundancy exists in high-yielding maize colonies. The characters of grain-filling were simulated by Richards model, and the photosynthetic characteristics and chlorophyll fluorescence of the leaves on ear position were determined to reveal the activities of photosynthesis after the removal of redundancy. The results showed that at optimal plant density and under high-yielding condition, both the redundant and non-redundant types had leaf redundancy. The characterization of grain-filling by Richards model indicated that appropriately removing redundant leaves could increase the net photosynthetic rate and solar energy use efficiency of the leaves on ear position, extend the active period of grain-filling, and enhance the grain yield.

Zhu Y.-G.,Shandong Agricultural University | Dong S.-T.,Shandong Agricultural University | Zhang J.-W.,Shandong Agricultural University | Liu P.,Shandong Agricultural University | And 5 more authors.
Chinese Journal of Applied Ecology | Year: 2010

In order to investigate the effects of interplanting and direct seeding on the photosynthesis characteristics of summer maize and its utilization of solar and heat resources, two summer maize cultivars (Zhengdan 958 and Denghai 661) were planted in the farmlands of Denghai Seed Co. Ltd in Laizhou City of Shandong Province, with 67500 plants • hm-2 and three sowing dates. The above-ground biomass, plant growth rate, leaf area index, and net photosynthetic rate per ear leaf were measured to reveal the photosynthesis characteristics of test cultivars. In the meantime, the characters of grain-filling were simulated by Richards' model, and the solar resource utilization efficiency of the cultivars was calculated, in combining with meteorological data. Comparing with interplanting, direct seeding increased the grain yield by 1. 17%-3. 33%, but decreased the thousand-grain weight significantly. Growth stages were extended under earlier sowing. The leaf area index and net photosynthetic rate from flowering to 30 d after anthesis were significantly higher under direct seeding than under interplanting, but after then, they decreased faster. Direct seeding induced a higher accumulation of dry matter and a faster plant growth rate before and after flowering. Under direct seeding, the maximum grain-filling rate reached earlier, the starting potential was higher, but the grain-filling period, active grain-filling period, and Wmax were lower, compared with those under interplanting. Also under direct seeding, the total accumulative temperature and solar radiation during growth period decreased by 150-350 °C • d and 200-400 MJ • m -2, respectively, but the solar resource utilization efficiency of grain increased by 10. 5%-24. 7%. All the results suggested that direct seeding was superior to interplanting for the summer maize production under field condition. In order to enhance solar and heat utilization efficiency and excavate yield potential, it would be essential to improve the leaf photosynthesis efficiency and postpone leaf aging.

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