橡胶园砖红壤中磷和钾素径流流失特征研究

砖红壤是我国植胶区主要土壤类型,该区水土流失严重,养分的流失不仅造成了土壤肥力下降,还会引起地下水体富营养化。在自然降雨条件下,利用大型径流场田间小区试验研究橡胶园土壤中磷和钾素径流流失特征。结果表明:橡胶园土壤磷、钾素的径流流失量受降雨量的影响显著,钾素流失主要发生在雨季来临时前几次大暴雨及施肥后的第一、二场大暴雨;增施磷、钾肥可增加径流水溶性总磷和K+流失量及泥沙结合态磷的流失量,而对泥沙结合态钾的流失量无显著影响;磷和钾的流失均以泥沙携带为主,分别占流失总量的84.06%和70.98%,径流水溶性磷、钾素的流失所占比例较小;在供试条件下,施入的磷肥除部分随地表径流流失外,仍可在一定程度上保持土壤有效磷含量;而施用钾肥大多随降雨径流流失,对土壤速效钾含量无显著影响。     

施肥对闽西毛竹生物量及碳储量分布格局的影响

以闽西施用5 a竹林专用肥（一类）、5 a氮、磷、钾配方施肥（二类）、5 a有机肥（三类）、1 a竹林专用肥（四类）、1 a有机肥（五类）等不同施肥类型毛竹林为研究对象,以不施肥毛竹林（六类）为对照,研究了施肥对毛竹林生物量及碳储量分配格局的影响。结果表明： （1）施肥增大了毛竹生物量,表现为三类（91.18 t/hm2）＞一类（83.61 t/hm2）＞二类（71.38 t·hm2）＞五类（71.12 t/hm2）＞四类（65.13 t/hm2）＞六类（57.83 t/hm2）,施肥能够提高毛竹叶片、竹枝、竹秆等地上部分的生物量及其占毛竹总生物量的比例,增大毛竹地上/地下生物量的比值,且施肥5年（一、二、三类）＞施肥1 a（四、五类）＞不施肥（六类）;（2）不同施肥处理下毛竹碳储量为28.37～45.99 t/hm2,施用5 a有机肥（三类）最大,不施肥（六类）最小;竹秆是毛竹碳储量的主要贡献器官,而竹叶贡献率不足4％;与未施肥竹林相比,毛竹施肥后地上部分固碳总量有较大提升;（3）不同施肥处理下毛竹年净生产力、年固碳量和同化CO2量均表现为三类＞一类＞二类＞五类＞四类＞六类,年同化CO2量分别为41.42、41.17、30.99、23.47、20.69、20.00 t/（hm2·a）;施肥年限对毛竹年净生产力有较大影响,施肥5 a（一、二、三类）均能够显著提高毛竹年净生产力。     

添加生物质炭对酸性茶园土壤 pH 和氮素转化的影响

采用短期（46 d）室内好气培养方法,研究不同茶枝生物质炭添加量对茶园红壤、黄壤 pH 和氮素净转化速率的影响。生物质炭用量设5个水平：H0（0 t·hm－2）、H1（8 t·hm－2）、H2（16 t·hm－2）、H3（32 t·hm－2）、H4（64 t·hm－2）,生物质炭来源为茶树枝条。结果表明：培养结束时,与不添加生物质炭处理相比（H0）,添加生物质炭处理均可提高2种茶园土壤 pH 值,红壤增加0．24～1．20个单位,黄壤增加0．26～1．34个单位,pH 提高幅度与生物质炭用量呈正相关。添加生物质炭后显著降低了茶园土壤氮矿化量、净氮矿化速率和净硝化速率（P ＜0．05）,特别是 NO－3-N 含量,抑制茶园土壤硝化作用,抑制程度随生物质炭添加量增加而增强。红壤茶园土壤矿质态氮含量、净氮矿化速率及净硝化速率要高于黄壤,黄壤茶园土壤矿质态氮表现为净固持;相同添加量的生物质炭对红壤氮素转化的影响大于黄壤。综上所述,短期培养条件下,生物质炭能显著降低茶园土壤矿质态含量,抑制土壤硝化作用,其抑制效果因生物质炭用量和土壤类型而异。     

土壤水分对槟榔幼苗净光合速率和蒸腾速率的影响

为实现槟榔幼苗标准化灌溉,采用盆栽实验,设置5个水分梯度[土壤相对含水量（30±5）％～（90±5）％],测定不同水分条件下槟榔幼苗的净光合速率（Pn）、蒸腾速率（Tr）、空气相对湿度（RH）、空气中CO2浓度（Ci）和气孔导度（Cond）等参数,研究各个因子对槟榔幼苗净光合速率（Pn）、蒸腾速率（Tr）的影响,采用回归分析分别拟合土壤水分与其净光合速率、蒸腾速率的数学模型。结果表明：（1）土壤相对含水量＜60％时,影响槟榔幼苗Pn的主要因子是Cond、RH;土壤相对含水量≥60％时,影响槟榔幼苗Pn的主要因子是Ci、RH。（2）土壤相对含水量45％～60％时,影响槟榔幼苗Tr的主要因子是Cond、Vpdl;土壤相对含水量60％～70％时,影响槟榔幼苗Tr的主要因子是Cond和Ci;其余水分条件下影响槟榔幼苗Tr的主要因子都是Cond。（3）根据本次研究,拟合土壤水分对槟榔幼苗净光合速率和蒸腾速率的数学模型分别为Pn=-0.001 8x2+0.293 9x-5.567 9,R2=0.998 1;Tr=-0.001 6x2+0.265 2x-6.008 3,R2=0.943 8。     

仙游县1998年早季杂交水稻新组合比较试验

仙游县于1983年开始引入早杂威优35,取得较好的增产效果,早稻杂优种植面积迅速增加,至1998年全县早稻杂优面积达1．03万hm2,占早稻总面积的88％。全县早稻平均单产由1984年的6．42t／hm2提高到1990年的6．93t／hm2（6a增长0．51t／hm2）;但此后的增产速度就明显缓慢...     

海南岛东北部5种森林土壤有机碳分布特征

为揭示海南岛东北部森林土壤有机碳分布特征,本文对该区湿加松林（Pinus elliottii×P. caribaea）、木麻黄林（Casuarina equisetifolia）、椰树林（Cocos nucifera）、次生林和混交林等5种典型森林土壤有机碳含量和储量进行了比较研究。结果表明,5种森林0~100 cm土壤有机碳平均含量差异显著（P<0.05）,其中次生林最高,为3.78 g/kg,木麻黄林最低,仅有0.90 g/kg;5种森林0~100 cm土壤有机碳储量分别为次生林46.06 t/hm ²、混交林40.52 t/hm ²、湿加松林39.08 t/hm ²、椰树林31.26 t/hm ²和木麻黄林15.22 t/hm ²。浅海沉积土上的次生林、滨海沙土上的混交林均具有相对较高的土壤有机碳储量,分别显著地高于同一母质上的椰树林和木麻黄林（P<0.05）。综上,该区不同类型森林的建立深刻地影响了土壤有机碳库储量,次生林和混交林的建立可能有助于该区增加土壤固碳。     

古田马铃薯氮磷钾肥料效应及其施肥指标体系的研究

为了解古田马铃薯N、P、K肥料施用效果, 通过马铃薯“3414”田间肥效试验和土壤养分分析,建立古田土壤马铃薯养分丰缺指标。结果表明：古田县冬种马铃薯在现有土壤养分肥力水平下,施用N、P、K 肥料依然是提高马铃薯产量和增加经济效益的主要措施。施用N、P、K肥料分别增产24.0％、10.8％和22.1％, 施肥处理增加单产的效果依次是N＞K＞P。施肥增加经济效益依次是P＞N＞K。N、P2O5、K2O的产投比分别为12.6、13.7和9.3。对古田县冬种马铃薯而言,马铃薯土壤低肥力等级N、P、K养分临界指标含量分别是：＜109.9、6.4与92.3 mg/kg;而高肥力等级土壤N、P、K养分临界指标则分别为：＞248.9、49.6和151.8 mg/kg。古田县冬种马铃薯平均最高产量的N、P、K施用量分别为：（205.1±31.3）、（88.5±40.5）和（302.1±57.3）kg/hm2 ;取得最佳经济产量的N、P、K施用量分别为：（178.4±42.8）、（68.2±37.3）与（265.2±79.1）kg/hm2;三要素最佳比例为1 ∶ 0.4 ∶ 1.5。     

基于渗漏池法研究施肥对东北中部雨养区玉米氮素地下淋溶的影响

2010~2013年,对东北玉米土壤氮素地下淋溶年际发生规律和氮排放强度进行研究。结果表明,淋溶年平均发生7~8次,受降雨影响较大,其中6月和7月的淋溶次数占全年的2/3。农田氮素淋溶排放强度年际间差异较大,最高值与最低值差8倍左右,农田本底(不施肥)流失量平均为5 kg/hm2,各施肥处理在4.53~7.17 kg/hm2,农田本底氮素流失70%以上,整体来看,北方农区氮素的地下淋溶强度不高,约占施氮量的5%左右,受降雨、施肥、土壤类型等综合因素的影响。     

热研15号刚果臂形草的研究与利用

臂形草属[Brachiaria(Trinius)Grisebach]牧草是一种重要的放牧型牧草和水土保持植物,但原有品种已不能满足生产上的多样性需求,而热研15号刚果臂形草耐干旱,耐酸瘦土壤;侵占性强;耐践踏、耐重牧,与豆科混播亲和力强,适合草地建设、水土保持和果园田间;产量高,平均年产量达到209.87t/hm2·a,营养价值和饲用价值高,分别达14.12%和17.42%,具有良好的开发和利用价值。     

“佳禾早占”的特征特性及栽培技术

“佳禾早占”是厦门大学生物学系水稻育种组于1989年用[（E94×大粒种）FS×713）×外引30（成熟花粉经r一射线9．3Gy辐照）复合杂交，经多代系统选择，于1996年早季从800多个株系中筛选出米质可与晚米媲美的优质早稻新品种。一、主要特征特性1·产量表现：一般6～6．75t／hm’，ig96年晚季在集美厦大农场试种1．3亩，在单本插的情况下，经厦门市科委组织专家现场实割验收平均每公顷7．125t。1997年参加福建省早季品种区试，平均每公顷5．933t；并在省早季品种区试总结会议上，推荐参加全省示范。同年早季参加厦门市早季水稻11个点区试平…     

三峡地区玉米降水生产潜力及适宜开发研究

对三峡地区玉米降水生产潜力及适宜开发度进行研究。结果表明:在玉米全生育期,自然降水总量的41.9%用于农田蒸散。坡地与平地相比,坡地地表径流量占降水总量的28.3%,平地地表径流量占降水总量的12.3%;耗水系数平均为0.136mm/(kg·hm2),比平地低0.007mm/(kg·hm2)。影响玉米降水生产潜力的主要障碍因子是施肥水平、降水量和土壤侵蚀。随着施肥水平的提高,降水生产潜力增大,且施肥水平对坡地降水生产潜力的影响比平地更加明显;水土流失增加,降水生产潜力降低,降水量对降水生产潜力的贡献值为-3.135kg/(mm·hm2),即每减少降水量1mm,坡地降水生产潜力平均下降3.135kg/hm2。在现有技术、土壤、投入水平及管理条件下,三峡地区大田玉米降水生产潜力开发程度(MKD)较低,坡地约60%～65%,平地约65%～70%。坡地玉米降水生产潜力适宜开发度(SKD)可达80%,平地可达90%。可开发程度(KKD)坡地平均为17.5%、平地平均为17.9%,平地降水生产潜力可开发程度比坡地稍大。     

Reduction of runoff and soil loss over steep slopes by using vetiver hedgerow systems

Vetiver hedgerow system has potential for reducing runoff and soil loss especially on steep slope areas, but the dynamics of these reductions are not fully understood. This research was conducted to determine reduction in runoff and soil loss by vetiver hedgerow system. Vetiver hedgerow systems with three vertical intervals of hedgerow were tested on three land slopes and compared with the case without hedgerow for six simulated rainfall amounts. The vetiver hedgerows reduce runoff volume and soil loss by 31–69 and 62–86 %, respectively compared to the case without vetiver hedgerow. Runoff volume increases with rainfall amount, and hence increases soil loss. Therefore soil loss increases with land slope, runoff volume, rainfall amount, and vertical hedge interval. Two final equations for estimating soil loss are presented in this study. The first equation contains parameters of runoff volume, land slope, and vertical hedge interval, while the second equation contains rainfall amount instead of runoff volume. The correlation coefficients between estimated soil losses and the experimental data in this study and in the literatures were found to be 0.94 and 0.90 for the first and second equations, respectively.     

橡胶幼龄林下间作菠萝对水土流失的影响

本实验旨在探讨橡胶幼龄林下间作菠萝对水土流失的影响。采用单因素随机区组设计的方法,测定了顺坡种植菠萝,横坡种植菠萝和不间作(对照)条件下的径流量及土壤侵蚀量。结果表明：西双版纳雨季时,5～10月间,横坡和顺坡种植菠萝径流量均低于不间作菠萝,顺坡种植在6～9月间的径流量都高于横坡种植;6～10月间,顺坡种植和横坡种植菠萝能显著降低林间侵蚀量,横坡种植在6～9月间侵蚀量均低于顺坡种植;径流量、侵蚀量和降雨量的变化趋势基本相同;顺坡和横坡种植的总径流和总侵蚀量均显著减少。说明橡胶幼龄林下横坡种植菠萝可以有效减轻林地水土流失。     

Evaluation of soil erosion risk for watershed management in Shenmu watershed,central Taiwan using USLE model parameters

This study compiles the latest regional topographic data from field investigation and remote-sensing images to recalculate parameters of the universal soil loss equation (USLE) model of the Shenmu watershed; also to compensate for reduced accuracy of this model on small-scale slopes, this study incorporates soil erosion pin data which were collected periodically to measure the extent of soil erosion. Firstly, this study utilized the USLE model and soil erosion pin data to compare the soil erosion potential of the Chushui and Aiyuzi subwatersheds and concluded that soil erosion drastically increased if accumulated rainfall exceeded 200 mm; also, erosion depths were greater in the Aiyuzi subwatershed while estimated total erosion volume was higher in the Chushui subwatershed; this was attributed to the larger area of Chushui subwatershed and based on field measurements which supported the results of the USLE model. Secondly, this study utilized modified USLE model to compare the extreme event erosion resulting from typhoon Morakot which revealed that high rainfall intensity and long-duration rainfall events can generate large volume non-point sources of sediment that is estimated to far exceed 7–10 times of the annual soil erosion. Thirdly, this study related the C parameter of the USLE model to the existing land use in the Shenmu watershed using current, real data. Finally, this study established a post-typhoon Morakot soil erosion risk map composed of five categories of risk which was compared with post-event land cover to suggest high-erosion risk zones that may require further monitoring, remediation, and engineering measures to limit soil loss.     

Application of USLE for the prediction of nutrient losses in soil erosion processes

Soil erosion in agricultural fields affects not only land productivity but also water environment down stream. Many investigations have been made for the prediction of soil erosion processes. The Universal Soil Loss Equation (USLE) has been applied broadly for the prediction of average annual soil loss from upland fields. However, there are few reports concerning the prediction of nutrient (N, P) losses based on the USLE. Thus, the objective of this study is to propose the prediction equation of nitrogen and phosphorus losses during soil erosion processes on the basis of the USLE. In order to predict total nitrogen and phosphorus losses, the coefficients for total nitrogen or phosphorus transfer are derived on the basis of results from experimental field plots. Three bare-cover USLE plots with different amounts of granular chemical fertilizer were installed in an experimental upland field. There was a tendency for the coefficient of total nitrogen or phosphorus transfer to increase with the average concentration of total nitrogen or phosphorus in the soils. It follows that the more granular chemical fertilizer applied caused a higher coefficient of total nitrogen or phosphorus transfer in the calculations. Moreover, the coefficients in heavily fertilized plots were higher than 1.0. Through this investigation, it became clear that the nutrient losses during soil erosion could be predicted on the basis of the coefficient of total nitrogen or phosphorus transfer along with other soil erosion parameters.     

Effect of surface cover on the reduction of runoff and agricultural NPS pollution from upland fields

In this study, two types of simulations were performed. First, indoor rainfall simulation revealed that runoff ratio (0–63.3 %) decreased dramatically with surface cover, compared with no surface cover condition (55–85.3 %), and sediment load and concentration also decreased. With additions of PAM, sawdust, and rice hull to rice straw mat, the runoff ratio decreased to 52.8, 36.6, and 53.2 %, compared with only rice straw mat condition (runoff ratio of 63.3 %). When gypsum was added, no runoff was observed in case of rainfall intensity of 30 mm/h. Under 60 mm/h rainfall condition, 50 % or more runoff reduction was observed. These could be explained in that surface cover reduces detachment of soil particles and keeps infiltration rate by reducing surface sealing with detached soil particle which could happen under non-surface cover condition. Second, when rice straw mat was applied to soybean field, no runoff was observed until rainfall intensity of 5.8 mm/h or greater, while runoff was observed with rainfall intensity of 1.5 mm/h at no surface covered soybean field. In addition, 89.7–99.4 % of pollutant reductions were observed with rice straw mat at the soybean field. When rice straw mat with additions of wood shaves was applied to Chinese cabbage and radish fields, 4.3–75.8 % of runoff reductions and 28–80.8 % of pollutant reductions were observed. In case of Chinese cabbage, 122.1 % yield increase was observed and 153.4 % yield increase in case of radish.     

Mulching potatoes: Aspects of mulch management systems and soil erosion

Intensive potato production occupies much of the sloping arable land of Prince Edward Island, Canada, and is at the center of soil erosion concerns in this province. Corrective considerations have turned recent attention to mulching, but there is limited knowledge of its workability or effectiveness in potato systems. This study looks at the effect of mulching on soil loss from potatoes grown on standard erosion plots, and examines a relatively simple approach to assessing soil-surface splash detachment (splash erosion) under mulch-management systems with potatoes. Three sizes of splash cup (25, 50, and 100 mm in diameter) were used under simulated rainfall at 150 mm·h^?1 for 10 minutes to measure splash erosion on potato plots under mulch-management systems which, respectively, left surface coverage of ～ 5%, ～ 15%, and ～20%. The lowest straw coverage gave up to 56% more erosion than either of the two higher coverages. The 25-mm splash cup yielded 14% more sediment splash than the 100-mm splash cup on the basis of unit surface area of soil in the splash cup (unit area). Regression modeling of unit-area splash against straw cover showed an exponential decay in splash detachment with increasing straw cover. On the erosion plots, soil loss with mulching was half of what it was without mulching; and soil water retention was 5% greater with mulching.     

Influence of paddy rice terraces on soil erosion of a small watershed in a hilly area of Northern Vietnam

Soil erosion is the main cause of soil degradation in northern Vietnam. In this study, soil erosion was measured in 2 m² field plots, a 19.1-ha sub-watershed, and a 248.9-ha main watershed in Tam Quan commune, Tam Duong district, northern Vietnam during 2 years, i.e., 2004–2005. The main watershed includes lowland paddy fields, and is representative for watersheds in the northern Vietnamese landscape. Soil erosion was measured for eight events, at all the three scales to increase our understanding of erosional processes and to assess the effects of paddy fields within the main watershed. The results show that total discharge and sediment yield in both sub-watershed and main watershed were much lower than those in the field plots. Total discharge per unit area in the main watershed was higher than in the sub-watershed, because during the growing season, the paddies are filled with water and any rainfall on them therefore becomes runoff. Sediment yield in the main watershed fluctuated, depending on the soil erosion contribution from many sub-watersheds. Annual rainfalls in 2004 and 2005 were 1,172 and 1,560 mm, respectively, resulting in corresponding total discharges of 54 and 332 mm and total soil losses of 163 and 1,722 kg ha^?1 year^?1. High runoff volumes occurred in July, August, and September, but April, June, the last 10 days of September and October, were the susceptible periods for soil erosion in the study area because of low plant cover and many agricultural activities during these periods.     

海南油茶林土壤养分状况调查

为了给海南油茶的科学施肥提供参考，以五指山地区为重点调查了海南油茶林土壤的pH、有机质、全氮、碱解氮、全磷、有效磷、全钾和速效钾含量等养分状况。结果表明，海南油茶林土壤存在一定程度的酸化，碱解氮含量丰富，有机质、全氮和全钾含量中等，速效磷和速效钾含量偏低，全磷极度匮乏。海南油茶林土壤养分管理应根据土壤养分状况，实行配方施肥，防止土壤进一步酸化。     

基于 USLE 模型的松涛水库流域土壤侵蚀定量研究

利用 GIS 和 RS 技术并结合土壤流失方程（USLE）对松涛水库流域土壤侵蚀进行定量估算，设置情景模拟分 析流域土壤侵蚀控制方案。结果表明：每年潜在土壤侵蚀总量约 5 742.59×104 t，平均每年侵蚀模数约 3.67× 104 t/km2 ， 高出容许土壤侵蚀量和土壤平均侵蚀模数的 92 倍；年均土壤侵蚀量约 61.96×104 t，集中分布在橡胶林和林地；流域年 均土壤侵蚀模数为 394.89×104 t/km2 ，高于容许土壤流失量，土壤侵蚀面积占总面积 12.16%，空间分布不均，水库周边 及下游土壤侵蚀较强烈。情景模拟发现改变人工林的种植方式，如采用水平阶或鱼鳞坑来种植浆纸林和橡胶林每年能 减少土壤侵蚀量 21.38×104 t，土壤侵蚀面积可减少 85.36 km2 ；植被覆盖度的增加，每年能减少土壤侵蚀量 15.93×104 t， 土壤侵蚀面积可减少 51.65 km2 。