植物多样性格局作为生物多样性维持的一个重要方面可揭示群落构建的信息,反映物种对环境的适应性。结合样带调查和实验分析的方法,研究新疆艾比湖湿地自然保护区内水盐梯度下荒漠植物多样性格局及其与土壤环境因子间关系。结果表明:(1)...植物多样性格局作为生物多样性维持的一个重要方面可揭示群落构建的信息,反映物种对环境的适应性。结合样带调查和实验分析的方法,研究新疆艾比湖湿地自然保护区内水盐梯度下荒漠植物多样性格局及其与土壤环境因子间关系。结果表明:(1)高、低水盐样地(SW1,SW2)土壤容积含水量(SVWC)和电导率(EC)分别为16.65%和12.02 m S/cm及2.63%和1.91m S/cm,水盐变化主要影响草本和部分灌木群落的植物组成;(2)高水盐生境下植物群落无明显趋势性分布,低水盐生境下植物种依水盐和营养元素呈区域性分布。(3)高水盐生境下荒漠植物的多度分布呈对数正态模型,低水盐条件下符合Zipf模型,多度分布的变化反映了群落组成结构的水盐梯度响应;(4)SW1样地多样性总体显著高于SW2样地,土壤p H、SVWC和硫(S)对植物多样性有不同程度的极显著影响。综上可知,荒漠植物分布及多样性格局与土壤环境间关系呈一定的水盐梯度响应规律,本研究可为该地区植被恢复和土壤盐渍化治理提供科学依据。展开更多
旨在通过不同放牧强度下高寒小嵩草（AlpineKobresia parva（Nees）Wang et Tang ex Y.C.Yang）草甸和垂穗披碱草（Elymus nutansGriseb.）/星星草（Puccinellia tenuiflora（Griseb.）Scribn.et Merr.）高寒混播草地暖季草场植物初级...旨在通过不同放牧强度下高寒小嵩草（AlpineKobresia parva（Nees）Wang et Tang ex Y.C.Yang）草甸和垂穗披碱草（Elymus nutansGriseb.）/星星草（Puccinellia tenuiflora（Griseb.）Scribn.et Merr.）高寒混播草地暖季草场植物初级生产力、土壤养分含量以及牦牛生产性能的研究,为草地合理利用提供有益的依据。结果表明：牦牛个体增重与放牧强度均呈线性关系;高寒小嵩草草甸暖季草场最适放牧强度为1.26头/hm2,垂穗披碱草/星星草混播高寒混播草地暖季草场的最适放牧强度是7.23头/hm2;放牧强度对高寒混播草地速效氮和速效磷的影响不显著,对速效钾的影响显著（P〈0.05）;随着放牧强度的提高,高寒小嵩草草甸土壤有机质、有机碳、全氮、全磷的含量呈减小趋势;当放牧强度分别达到1.07头/hm2,1.08头/hm2和1.22头/hm2时,0～5 cm,5～10 cm,10～20cm土壤速效氮含量依此达到最小;随着放牧强度的提高,高寒小嵩草草甸禾草和莎草的比例下降,可食杂草和毒杂草比例增加,而高寒混播草地垂穗披碱草的比例降低,星星...展开更多
This study aimed to analyze the relationship between nutrient elements K, Ca, Mg, Cu, Mn, Zn and Fe in tobacco-planting soils and tobacco leaves from six main tobacco-producing areas, and to investigate the influences...This study aimed to analyze the relationship between nutrient elements K, Ca, Mg, Cu, Mn, Zn and Fe in tobacco-planting soils and tobacco leaves from six main tobacco-producing areas, and to investigate the influences of these elements on chemical composition and aroma components in tobacco leaves. Results showed that there were certain relationship between contents of nutrient elements in tobacco-planting soils and contents of corresponding elements in tobacco leaves; various elements exhibited different influences on the aroma quality of flue-cured tobacco. Based on the actual situation of nutrient contents in soils from different tobaccoproducing areas, contents of various elements in tobacco leaves should be regulated by soil fertilization and foliar spraying, thereby improving the aroma quality of flue-cured tobacco.展开更多
A field experiment was conducted to determine the response of a newly released cassava variety （TMS 98/0510） in Nigeria to three sources of organic manure （poultry waste, pig dung and goat dung at 10 t/ha）, two le...A field experiment was conducted to determine the response of a newly released cassava variety （TMS 98/0510） in Nigeria to three sources of organic manure （poultry waste, pig dung and goat dung at 10 t/ha）, two levels inorganic fertilizer （N：P：K 15：15：15 at 200 and 400 kg/ha） and a control treatment. The six treatments were compared in a randomized complete block design with three replications. Data were collected on yields and yield related agronomic and morphological traits. Data were also collected on soil nutrient content at planting and the content of N, P, K, Ca and Mg in the leaf stem and roots. The results showed that the soil used in this experiment was low in organic matter and other nutrients except available P. Inorganic and organic fertilizers significantly increased leaf area, however yield and growth related traits like plant height, number of leaves, stem yield, tuber girth, number of roots and harvest index were not significantly different among the treatments. Contrary to expectations manure and fertilizer treatments did not increase fresh root yield in this cassava variety. They did not also influence the content of N, P, K, Ca and Mg in the stem, leaf and root. This response suggests that cassava varieties bred for farmers＇ conditions in Nigeria, which are inherently low in soil nutrients, may not respond to additional nutrient input. Breeders should therefore select cassava for dual adaptation to low and high nutrient levels in the soil to meet the needs of a wider spectrum of farmers and to justify government and extension support for the use of input by farmers in Nigeria.展开更多
文摘植物多样性格局作为生物多样性维持的一个重要方面可揭示群落构建的信息,反映物种对环境的适应性。结合样带调查和实验分析的方法,研究新疆艾比湖湿地自然保护区内水盐梯度下荒漠植物多样性格局及其与土壤环境因子间关系。结果表明:(1)高、低水盐样地(SW1,SW2)土壤容积含水量(SVWC)和电导率(EC)分别为16.65%和12.02 m S/cm及2.63%和1.91m S/cm,水盐变化主要影响草本和部分灌木群落的植物组成;(2)高水盐生境下植物群落无明显趋势性分布,低水盐生境下植物种依水盐和营养元素呈区域性分布。(3)高水盐生境下荒漠植物的多度分布呈对数正态模型,低水盐条件下符合Zipf模型,多度分布的变化反映了群落组成结构的水盐梯度响应;(4)SW1样地多样性总体显著高于SW2样地,土壤p H、SVWC和硫(S)对植物多样性有不同程度的极显著影响。综上可知,荒漠植物分布及多样性格局与土壤环境间关系呈一定的水盐梯度响应规律,本研究可为该地区植被恢复和土壤盐渍化治理提供科学依据。
文摘This study aimed to analyze the relationship between nutrient elements K, Ca, Mg, Cu, Mn, Zn and Fe in tobacco-planting soils and tobacco leaves from six main tobacco-producing areas, and to investigate the influences of these elements on chemical composition and aroma components in tobacco leaves. Results showed that there were certain relationship between contents of nutrient elements in tobacco-planting soils and contents of corresponding elements in tobacco leaves; various elements exhibited different influences on the aroma quality of flue-cured tobacco. Based on the actual situation of nutrient contents in soils from different tobaccoproducing areas, contents of various elements in tobacco leaves should be regulated by soil fertilization and foliar spraying, thereby improving the aroma quality of flue-cured tobacco.
文摘A field experiment was conducted to determine the response of a newly released cassava variety （TMS 98/0510） in Nigeria to three sources of organic manure （poultry waste, pig dung and goat dung at 10 t/ha）, two levels inorganic fertilizer （N：P：K 15：15：15 at 200 and 400 kg/ha） and a control treatment. The six treatments were compared in a randomized complete block design with three replications. Data were collected on yields and yield related agronomic and morphological traits. Data were also collected on soil nutrient content at planting and the content of N, P, K, Ca and Mg in the leaf stem and roots. The results showed that the soil used in this experiment was low in organic matter and other nutrients except available P. Inorganic and organic fertilizers significantly increased leaf area, however yield and growth related traits like plant height, number of leaves, stem yield, tuber girth, number of roots and harvest index were not significantly different among the treatments. Contrary to expectations manure and fertilizer treatments did not increase fresh root yield in this cassava variety. They did not also influence the content of N, P, K, Ca and Mg in the stem, leaf and root. This response suggests that cassava varieties bred for farmers＇ conditions in Nigeria, which are inherently low in soil nutrients, may not respond to additional nutrient input. Breeders should therefore select cassava for dual adaptation to low and high nutrient levels in the soil to meet the needs of a wider spectrum of farmers and to justify government and extension support for the use of input by farmers in Nigeria.
