元谋干热河谷区旱坡地生态农业模式的水土保持效益研究

对元谋干热河谷区4种旱坡地生态农业模式的水土保持效益进行了系统的研究。结果表明：与对照模式“罗望子＋裸地”相比，建立的4种模式均体现了良好的水土保持效果，其中．“罗望子＋木豆＋柱花草”模式截持降雨。增加地表盖度．改善土壤物理性状，提高蓄水保水能力，防治水土流失效果最佳，其余3种模式均有明显的生态效益。根据需要．若重新对套入模式的主栽灌草层作物进行科学合理的搭配，重建后的优化复合生态农业模式，无论是生态效益，还是经济和社会效益都将得到充分的体现。     

干热河谷典型区土壤功能对不同植被恢复措施的响应

为研究干热河谷地区不同恢复措施下土壤功能的变化,分析了不同模式下土壤入渗和理化特征。结果表明,在乡土树种罗望子(Tamarindus indica)林下,木豆(Cajanus cajan)+象草(Pennisetum purpureum)模式的恢复效果最好,土壤团粒达60%～80%,表层有机质含量较对照提高了5.01倍,其入渗率较对照区提高14.43倍,最大吸持贮水量可达633.0t/hm2,明显高于其他模式,土壤性质的改善也提高了罗望子的生产力水平。其他恢复模式的土壤功能较差,但优于对照模式,表明土壤理化性质的改良取决于植物种类的选择和配置。     

罗望子人工林土壤有机碳在不同团聚体中的特征

研究了干热河谷地区不同种植方式的罗望子人工林内0-10,10-20,20-40 cm土层土壤团聚体中的有机碳分布特征.结果表明,在所有样地中,1～0.5,0.5～0.25 mm这2个径级的土壤团聚体有机碳最高,10～5 mm团聚体有机碳最低.不同种植方式的人工林土壤团聚体有机碳差异较大,其中以罗望子+乡土草本,罗望子+百喜草2种种植方式的团聚体有机碳最高,罗望子+余甘子混交林内最低,但罗望子+乡土草本方式的团聚体有机碳高于罗望子+百喜草方式.光板地土壤团聚体有机碳在3个土层的差异较小.     

元谋干热河谷旱坡地双链型罗望子-牧草-羊生态农业模式高效配套技术研究

生态环境脆弱、水资源短缺、土地退化严重、光热资源充足是元谋干热河谷的突出特点,双链型罗望子-牧草-羊生态农业模式是针对该区脆弱的环境条件,为保护和恢复退化生态系统平衡,发展区域经济提出的生态可持续发展方式。本文总结了在该区建立双链型罗望子-牧草-羊生态农业模式的高效配套技术,并分析了该模式的综合效益。     

辽西矿区废弃地水土保持技术研究

建立牧草、灌木、牧草+灌木3种植被恢复模式试验区,分析3种植被恢复模式对矿区废弃地土壤养分、地表径流系数、土壤侵蚀模数的影响。其中牧草+灌木模式对矿区废弃地土壤改良效果好于牧草、灌木2种模式;牧草、牧草+灌木2种模式地表径流系数没有明显变化,最小为0.24;牧草+灌木模式土壤侵蚀模数最小,为207.9 t/(km2·a);3种植被恢复模式均具有改良土壤、减小地表径流和土壤侵蚀的作用,牧草+灌木模式总体效果最好。     

果草套种对南方丘陵山地表层土壤微生物量碳氮及酶活性的影响

[目的]探究不同果草套种模式下0—10cm土层土壤微生物量碳、氮及酶活性的差异,为改善土壤肥力条件、促进桂林旅游城市生态循环农业经济的发展提供理论依据。[方法]在桂林潮田河流域大山口农业综合示范区内设置样地,采集表层(0—10cm)土壤样品,测定与分析不同果草套种模式下表层土壤微生物量碳、氮及酶活性的差异。[结果]0—10cm土层土壤氮磷钾、土壤微生物量碳氮和土壤酶活性大小基本表现为:阳朔金桔+牧草桂橙1号+牧草翠冠梨+牧草对照样地。其中,阳朔金桔+牧草模式对0—10cm土层土壤微生物量碳、氮含量和土壤酶活性的影响最为明显(p0.05)。相关性分析表明,土壤微生物量碳氮和3种土壤酶活性存在极显著正相关关系。[结论]果草套种模式特别是阳朔金桔+牧草模式对南方丘陵山地表层土壤肥力条件的改善作用较为明显。     

福建省紫金山金铜矿废弃地不同植被配置模式的恢复效果分析

为了研究不同植被措施对矿山废弃地的恢复效果,采用标准样地调查的方法,分别从植物种类、数量、覆盖度、物种多样性及生物量等方面对福建省紫金山金铜矿废弃地不同植被配置模式的恢复效果进行了全面的调查分析。结果表明,不同植被配置模式均可快速增加废弃地植物种类,恢复5a后不同配置模式的草本植物数量均高于未经开采的对照样地,其中马尾松+胡枝子+香根草+当地河滩草(模式B)最多,达到了25种;枫香+本地河滩草(模式D)和桉树+本地河滩草(模式E)物种丰富度指数M和Shan-non-Wiener及Simpson多样性指数较大,可较快地提高群落物种多样性;不同配置模式植被覆盖度均有较大提高,除马尾松+胡枝子(模式A)较低外,其他模式均达到85%以上;马尾松+胡枝子+香根草+本地河滩草(模式B)灌草层生物量最大,达到对照的15.81倍;结合聚类分析结果可得出,马尾松+胡枝子+香根草+本地河滩草(模式B),枫香+本地河滩草(模式D)和桉树+本地河滩草(模式E)3种植被配置模式对紫金山金铜矿废弃地植被恢复效果较好,可在矿山废弃地植被恢复中推广应用。     

黄土退耕坡地工程治理与林草优化配置模式研究

为使黄土退耕坡地植被快速恢复,减少水土流失,根据不同植物的生性特点,结合坡地不同的工程治理措施,研究提出了以草为主,草、树间作的治理模式,解决了退耕坡地当年裸露地表水土流失严重的问题。指出对于15°～20°的坡地,以大台田＋艹律草＋经济林治理模式最好,当年植被盖度可达47.2％,4年后可达75.9％,土壤侵蚀量较对照下降34.30％;对于20°～25°坡地,以隔坡梯田+艹律草+乔木生态林的治理模式最好,当年植被盖度可达33.9％,4年后达49.4％,土壤侵蚀量比对照下降67.04％;对于25°以上坡地宜采用大鱼鳞坑+冰草+灌木组合治理模式,当年植被盖度可达28.7％,4年后达36.3％,土壤侵蚀量比对照下降68.17％。三种模式均能有效地减轻雨滴对疏松表土的溅蚀,提高了土壤含水率和植被覆盖度,利于形成林草和谐共生的稳定群落。     

冬春季多年生牧草对富营养化水体的响应及净化效果研究

在室外条件下以8种多年生牧草为材料研究其在重度富营养化水体中的生长状况及生长期间对水体氮磷的削减。结果表明,8种牧草均能适应水生环境并快速生长。经过收割后,每1m2的坦克草浮床生长期内可从水体中吸收17.5g的氮和7.5g的磷。牧草修复水体后,其作为饲料的基本指标均符合国家标准。选取室外试验中生长状况较好的4种多年生牧草进行室内模拟实验,研究其对富营养化水体的修复效应。水体TN、TP、NH4+-N、NO3--N、NO2--N、COD在植物浮床系统处理下均显著下降,坦克草处理下去除率最高,对TN、TP、NO3--N、CODMn去除率分别达64.1%,92.1%,70.7%和80.7%。多年生牧草在冬春季对富营养化水体中的氮磷具有较好的净化效果,可作为水体生态修复的优良物种而使用。     

生态牧草筛选及其在生态果园应用的研究

总结了10年来福建省农业科学院与国外合作的红壤丘陵区适生草种研究和推广的主要成果，提出生态牧草的概念。阐述了筛选出的10余种优良牧草品种的特性、种植技术与模式以及推广应用的生态、经济和社会效益，生态果园模式与牧草套种技术及其应用效果，并分析了生态牧草在推广应用中存在的问题。     

Potential of feed-food double-cropping in central highlands of Ethiopia

The potential of feed-food double-cropping was evaluated at Ginchi, Ethiopia, for two years with the objective of evaluating herbage yields of fodder crops and the subsequent effects on grain yields of chickpea and grass pea. Early maturing oat (79Ab382 (TX) (80SA95); 79CP84 (Coker SR. res) 80SA130; SRCP X 80Ab2806; C7512/SRCP X 80Ab 2252 and CO X SRCP X 80Ab2291) and common vetch (Acc. No. 2490; Acc. No. 2742) were selected and planted on lands reserved for chickpea/grass pea at the start of the main rainy season. Following forage harvest, chickpea and grass pea were planted on all plots and control fallow plot (farmers’ practice). A randomized complete block design with three replicates was used. Vigor (potential growth), plant height, herbage yield of forage crops, and grain yields of chickpea and grass pea varied across years. Higher average herbage yield (3.36 t ha^–1) was obtained from oat–common vetch mixtures compared to a fallow system (1.11 t ha^–1). Moreover, grain yields of chickpea and grass pea grown as a double-crop following oat–common vetch were more or less similar to yields obtained under a fallow system except in the case of chickpea following T6 (oat SRCP X 80Ab2806 × Vicia sativa acc. No. 2742). From this study, it was concluded that double-cropping of early-maturing, improved forage crops and residual soil moisture-based planting of chickpea and grass pea could improve feed availability, and labor and land productivity.     

塔里木河中下游退耕还林还草综合生态效益评价研究

以恢复生态学为理论指导,区域可持续发展为目的,根据塔里木河中下游退耕还林还草的现状,建立退耕还林还草综合生态效益的评价指标体系和评价模型,应用层次分析法(AHP)原理推测塔里木河中下游生态林、经济林、牧草等3种退耕还林还草类型的综合生态效益指数,并与农田生态系统进行了对比研究。研究结果表明生态林、经济林、牧草等退耕还林还草类型的生态效益均大于农田生态系统。其生态效益指数排序为:经济林>生态林>牧草>农田。这一研究结果将为塔里木河中下游退耕还林还草工程规划、布局等经营方式提供理论依据。     

滇东南石漠化山地不同退耕还林模式土壤地力变化初探

通过对滇东南西畴县石漠化山地12种不同退耕还林模式的土壤进行定点观测和地力变化分析,结果表明:土壤物理性状有很大改善,土壤抗蚀性和储水性增强,土壤养分提高,土壤吸收保存养分离子能力增强。对于提高地力而言,墨西哥柏+金银花、花椒+白枪杆、川滇桤木+红三叶、川滇桤木林、花椒+大白脉根和墨西哥柏+紫花苜蓿等6种模式较佳,值得在石漠化山地推广。     

渭北黄土高原果园生草地旱季土壤水分特征研究

在黄土高原渭北苹果园,分析多年生鸡脚草（Dactylis glomerata L.）、百脉根（Lotus corniculatu L.）、小冠花（Coronilla varia L.）三种牧草对0—200 cm土层含水量的影响。结果表明:冬春季节草地表现出明显的保墒性,而进入春季以后,随着牧草的萌发又表现出强烈的耗水性,4月10日—5月31日鸡脚草、百脉根、小冠花地块土壤总耗水量分别为99.57,104.81,82.13 mm,远高于行间裸地同期在该土层的耗水量（24.19 mm）,三种牧草的耗水能力大小依次为:百脉根 > 鸡脚草 > 小冠花。生草地块土壤稳定层对活跃层水分补偿作用明显,活跃层贮水量每减少1 mm,鸡脚草、百脉根、小冠花的相对稳定层贮水量分别减少0.60,0.60,0.73 mm。     

Ureide production by N2-fixing and non-N2-fixing leguminous trees

Xylem-sap and stem and leaf extracts from 35 species, comprising 14 genera, of leguminous trees were analyzed for ureides, nitrate and -amino acids. Trees were either inoculated with Rhizobium or fertilized with NH₄NO₃. The dominant form of soluble N in stem and leaf extracts and xylem sap was 2-amino acids. Certain non-N₂-fixing species, i.e. Tamarindus indica and Adenantherapavonina, produced significant amounts of ureides. Several N₂-fixing species. Mimosa scabrella, Sesbania grandiflora. Acacia mearnsii and Gliricida sepium, grown on mineral-N had higher absolute amounts of ureides in both extracts and exudates than did most nodulated species. Nodulated A. meamsii and S. grandiflora, had the highest amounts of ureides in xylem sap. The relative abundance of ureides in stem and leaf extracts was lower than in xylem sap, but was correlated. Results indicated that the presence of ureides, per se, was not a reliable indicator of N₂-fixing activity. Moreover, the relative abundance of ureides in most of the species tested was too low to use as a presumptive test for, or as a means of, estimating N₂ fixation.     

NODULATION,NITROGENASE ACTIVITY,AND DRY WEIGHT OF CHICKPEA AND PIGEON PEA CULTIVARS USING DIFFERENT BRADYRHIZOBIUM STRAINS

Chickpea [Cicer arietinum (L.)] and pigeon pea [Cajanus cajan (L.) Millsp.] were grown outside in large clay pots from 1992 to 1995 in Edmond, Oklahoma. Plants were studied to evaluate nodulation, nitrogenase activity, and shoot dry weight (DW) of ‘ICCV-2’ and ‘Sarah’ chickpea inoculated with multistrain, TAL 1148, and TAL 480 Bradyrhizobium, as well as ‘Georgia-1’ and ‘ICPL-87’, pigeon pea inoculated with multistrain TAL 1127, and TAL 1132 Bradyrhizobium. Following wheat [Triticum aestivum (L.) emend. Thell.] harvests in the spring, legumes were planted in the summer and harvested at three successive dates during the following months. Leaves and stems from remaining plants were incorporated into the soil after the last harvest. Across year, chickpea measurements were sensitive to temperature and precipitation whereas pigeon pea measurements were sensitive to length of growing season as well as climate. Pigeon pea consistently demonstrated higher nitrogen-fixing capacity and shoot DW compared with chickpea. Nodule and shoot DW of both species increased with plant age whereas nodule count and nitrogenase activity generally increased with plant age and leveled off or decreased at flowering. Sarah chickpea demonstrated higher nodule count and nodule DW than ICCV-2, as did the Georgia-1 pigeon pea compared with ICPL-87. Shoot DW of Georgia-1 pigeon pea was generally higher than that of ICPL-87. Multistrain inoculum improved nodulation and shoot DW of chickpea, and TAL 1127 improved nodulation of pigeon pea compared with other treatments. These results indicate that specific chickpea and pigeon pea cultivars, along with appropriate Bradyrhizobium strains, may improve nitrogen fixation and DW of these species.     

淮北地区5种不同植物群落土壤呼吸研究

选取河南西平杨树人工林生态系统中5种不同植物群落土地为研究对象,利用Licor-8100土壤呼吸测定系统对其土壤呼吸进行了连续观测,分析、比较5种不同植物群落土壤呼吸的差异及其影响因素。研究结果表明:（1）5种植物群落下土壤呼吸有所差异,但其日变化及年内变化趋势大致相同,均与土壤温度变化趋势一致,呈单峰曲线,其土壤呼吸大小顺序为:8 m行宽林间小藜—牛筋草地 > 2 m行宽林间苍耳地 > 8 m行宽林间水蓼—灰灰菜地 > 8 m行宽林间苍耳地 > 2 m行宽林间裸地;（2）采用土壤温度和湿度单因素模型（R_s=ae^bT_s或R_s=aW+b）进行分析:土壤温度和土壤含水量分别解释了不同植物群落土壤呼吸季节变化的41%~79%和2.3%~21%;而采用双因素模型分析（R_s=ae^bT_sW^c）,土壤温湿度共同解释了土壤呼吸速率季节变化的49.1%~86.7%,表明不同植物群落的土壤呼吸均受土壤温度和土壤含水量的共同影响;（3）运用Q₁₀=e^10b模型分析,Q₁₀值大小顺序为:8 m行宽林间小藜—牛筋草地（2.47） > 2 m行宽林间苍耳地（2.3） > 2 m行宽林间裸地（2.7） > 8 m行宽林间水蓼—灰灰菜地（2.59） > 8 m行宽林间苍耳地（2.22）,且5种不同植物群落下土壤呼吸Q₁₀值均表现为春季 > 冬季 > 秋季 > 夏季,即土壤呼吸温度敏感性随着温度的升高呈现出降低的趋势。     

闽北山区红壤丘陵开发地生态恢复与综合利用模式构建及其应用研究

山地生态系统的退化不仅是一个生态问题，也是一个经济问题。生态恢复重建不能仅仅就环境退化问题而开展生态功能的恢复重建，却而不去考虑经济恢复重建和区域脱贫与持续发展问题。根据红壤丘陵开发地退化成因分析和区域社会经济文化状况，建立了以水土保持为核心，“林果草牧沼菌”有效链接的治理模式，以草保土养地，以草带动地方产业发展．实现生态恢复与经济发展的双赢。     

Dinitrogen fixation and growth responses to phosphorus and aluminum application in pigeon. pea (Cajanus cajan L.)

Abstract

Responses to aluminum phosphate (Al-P) and superphosphate (Sup-P) application in terms of dry matter production by pigeon pea and soybean were compared under field conditions. The effect of aluminum on growth and symbiotic dinitrogen fixation was examined under hydroponic conditions. In a field experiment, Al-P application significantly increased whole plant dry weight and P amount in pigeon pea, whereas in soybean, Al-P application had no significant effect on the two parameters. The results indicate that P absorption ability from Al-P is higher in pigeon pea compared to soybean. With Al-P application, leaf and whole plant Al concentration in pigeon pea significantly increased unlike in soybean.

Under hydroponic conditions, 50 nig L^?1 Al application increased the plant weight of pigeon pea while it decreased that of soybean. This treatment decreased the total nodule activity of soybean more appreciably than that of pigeon pea. Under the Al treatment conditions, whole plant P amount increased in pigeon pea, whereas it decreased in soybean, and the amount of Al increased more appreciably in pigeon pea, most of which was deposited in roots.

These results suggest that compared to soybean, pigeon pea displays a higher ability to absorb P from P compounds with a low solubility i.e. Al-P and that it is more tolerant to Al toxicity.