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The leaf nutrient, biomass and carbon reserve of 9-year-old Populus×euramericana cv. ‘74/76’ stump grafting stand with 26-year-old P.×xiaozhuanica W.Y.Hsu et Liang cv.‘Popularis’as rootstock, 26-year-old P.×xiaozhuanica W.Y.Hsu et Liang cv.‘Popularis’ and 9-year-old P.×euramericana cv. ‘74/76’ planting stands were compared. The result showed that the average increment and the annual average increment of stump grafting stand were greater than the two planting stands. The total nitrogen content in leaves of stump grafting stand was the highest, and it was 1.26 times and 1.05 times as much as that of the planting stands of Populus×xiaozhuanica W.Y.Hsu et Liang cv.‘Popularis’ and P.×euramericana cv. ‘74/76’ separately. The total phosphorus content of stump grafting stand was 1.3 times as much as that of planting stand of 26-year-old P.×xiaozhuanica W.Y.Hsu et Liang cv.‘Popularis’, but there was little difference between stump graftin stand and planting stand of 9-year-old P.×euramericana cv. ‘74/76’. The total potassium of stump grafting stand was 46.6% and 95.8% lesser than that of the planting stands of P.×xiaozhuanica W.Y.Hsu et Liang cv.‘Popularis’ and P.×euramericana cv. ‘74/76’. The biomass of aerial parts and the biomasses of trunk, branches and leaves of stump grafting stand were 1.84, 1.80, 1.76, and 3.00 times as much as that of planting stand of P.×euramericana cv. ‘74/76’ separately. The total root biomass of the stump grafting stand was 1.42 times and 7.68 times as much as that of planting stands of 26-year-old P.×xiaozhuanica W.Y.Hsu et Liang cv.‘Popularis’ and 9-year-old P.×euramericana cv. ‘74/76’. There was an obvious advantage in carbon reserve from all the parts of the stump grafting stand and the carbon sequestration capacity was the highest, which was 2.66 times and 1.62 times as much as that of planting stands of 26-year-old P.×xiaozhuanica W.Y.Hsu et Liang cv.‘Popularis’ and 9-year-old P.×euramericana cv. ‘74/76’. These showed that the stump grafting stand had more advantages than planting stands. 相似文献
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刘志仁 《中国农村水利水电》2007,(9):59-62
为了探寻陕西本省粮食产销平衡出路,采用实证研究方法,通过对陕西省基本农田整治的历史和现状考察,粮食生产对基本农田的依赖度分析,认为目前陕西省科技进步对粮食增产的贡献率较低,粮食需求对省外的依赖度正在加大,必须有足够的高标准的基本农田作支撑,到2010年需求量应达到286.87万hm2,才能确保陕西本省粮食产销平衡。据此,因地制宜地设计了陕西省基本农田整治的具体途径,并在深入调研的基础上规划出基本农田整治的有效对策措施。 相似文献
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当前陕西省基本农田总量不足,分布不均,标准偏低,保护不力。要确保陕西省粮食产销平衡,必须有足够的高标准的基本农田作支撑,到2010年需求量应达到286.87万hm2。据此,需因地制宜地规划陕西省基本农田建设的具体途径;需在深入调研的基础上进行投资估算和效益预测;需制定相应的制度保障。 相似文献
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陕北能源开发与生态环境保护法律对策研究 总被引:1,自引:0,他引:1
刘志仁 《干旱区资源与环境》2009,(1)
陕北生态环境区可分为风沙滩地区和黄土丘陵沟壑区。风沙滩区的防沙治沙问题和黄土丘陵沟壑区的水土保持问题是陕北能源开发以前就存在的生态环境老问题。陕北能源开发引起的生态环境新问题主要是地貌和植被破坏严重,生态环境退化;地面塌陷、地下水位下降,居民生活受到影响;水土流失、土地沙化、自然灾害增加;废水、废气超标排放。陕北能源开发过程中生态环境日趋破坏的法律原因是生态补偿过于概括,缺乏可操作性;税收法律法规及地方规章规定的资源税率太低,税收分配比例不合理;环境影响评价制度的要求未能被全面适用。陕北能源开发中进行生态环境保护应选择的法律对策是坚持生态效益与经济效益相统一的环境法原则;完善生态环境法补偿机制;提高陕北资源税率,并在分配比例上适当照顾资源开发区人民的利益;制定环保产业规章制度,研究和引进先进的生产工艺。 相似文献
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日本用针刺疗法医治母猪不孕症获得成功 总被引:1,自引:0,他引:1
近年来,日本兽医界十分重视中兽医的研究,曾多次派专家来华学习,并不断将中兽医医术应用到畜牧业生产中。1981年5月 相似文献
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察右前旗地处阴山山脉前山丘陵区,属于高寒旱作区,昼夜温差大,春季干旱,风沙大,晚霜期长,在这样的气候条件下种植甜菜,干旱已成为春季抓苗难制约甜菜生产的重要因素。经过多年生产实践,现已总结出一套旱地甜菜覆膜穴播栽培技术。1997年,旱作甜菜覆膜面积达4... 相似文献