Phosphorus is one of the major constraints to karst grassland productivity. Understanding the effects of different fertilization practices on soil phosphorus dynamics is essential for enhancing phosphorus bioavailability and rational management of soil phosphorus in karst grasslands. Here, we investigated the effects of fertilizers and manures on soil bioavailability of phosphorus fractions and explored the relationship between soil properties and soil phosphorus fractions. The four fertilizer application designs were as follows: control (CK; no fertilizer or manure); fertilization (F); manure application (M); fertilization and manure application (FM). The results showed that total phosphorus (TP) concentration was elevated by 23%, 1%, and 42% in F, M, and FM treatments, respectively, compared with CK. F and FM treatments enhanced the total inorganic phosphorus (Pi) concentration by 65% and 66%, respectively, while M and FM treatments enhanced the total organo-phosphorus (Po) concentration by 21% and 35%, respectively. FM treatment elevated bioavailable P, active Po, secondary mineral P, primary mineral P, and occluded P by 69%, 39%, 50%, 31%, and 41%, respectively. Fertilizers inhibited soil acid phosphatase activity, whereas alkaline phosphatase did not respond significantly to fertilizer management in low-latitude karst regions. SOM, TN, AP, and MBP are the key factors affecting the bioavailability of phosphorus fractions. The combined application of fertilizer and manure is the most beneficial measure for enhancing soil phosphorus bioavailability. This research helps deepen our understanding of soil phosphorus dynamics in the karst areas and provides a basis for further enhancement of nutrient availability and vegetation productivity of grassland ecosystems.

The biggest obstacle to economic development in karst areas comes from the ecological crisis, so healthy soil and adequate food are important. Soil nitrogen (N) is an important factor in maintaining soil quality. Understanding the changes in soil N fractions and enzyme activities under different management practices is important to maintain sustainable pastureland in karst areas. In this study, we investigated how grazing and fertilization affect different soil nitrogen fractions and enzyme activities of karst pastureland. The four treatments were unused land (UL, undisturbed utilization), abandoned-grazing pastureland (APL, grazing for three years followed by abandonment for six years), grazing pastureland (GPL, controlled grazing without fertilizer) and fertilized-grazing pastureland (FGPL, controlled grazing + fertilizer), with the aim of determining the management practices that is most beneficial to soil N in the area. Our results indicated that FGPL is the most beneficial in enhancing soil N fractions. This is reflected in greater total nitrogen (TN), alkaline driven nitrogen (NOH), inorganic nitrogen (TON), anaerobic mineralized nitrogen (The average increase in each soil layer over UL was 1.43 times; TMN), microbial biomass nitrogen (The average increase in each soil layer over UL was 3.51 times; MBN), amino acid nitrogen (AAN), amino sugar nitrogen (ASN), acidolyzed unknown nitrogen (TUN) and unacidified nitrogen (AIN) in FGPL soils. Likewise, greater enzyme activities were also found in nitrogen conversion-related enzymes (soil urease (S-UE), soil N-acetyl-& beta;-D-aminoglucosidase (S-NAG), nitrate reductase (S-NR), and soil acid protease (S-ACPT)). In addition, the combination of grazing and balanced nutrient inputs slowed soil acidification and maintained high levels of total phosphorus (TP) and total potassium (TK). In contrast, the soil N fractions responded significantly to APL (low TN and plant effective nitrogen), while insufficient conversion capacity (enzyme activity, MBN) was the main reason for the compromised soil N availability at GPL. Government policy makers and livestock producers should encourage controlled grazing with proper fertilizer supplementation, and avoid prolonged abandonment of grazing lands.

为探明喀斯特地区不同草地根系动态及其对石漠化的响应,本文以3种不同石漠化程度（潜在、中度和强度）的草地为研究对象,采用连续根钻法和分解袋法,于2017年3月—2018年1月,分析了不同石漠化草地的根系垂直分布、季节动态、分解、周转及其与土壤因子的关系。结果表明,3种石漠化草地的根系生物量随着土层的深度增加呈逐渐降低的趋势,潜在和中度石漠化草地的根系生物量均呈现明显的单峰型季节变化,强度石漠化草地的根系生物量变化不显著。3种石漠化草地的根系分解速率受土壤有机碳、全钾、全氮、含水量、电导率、温度等的影响显著,随分解时间均表现为"快—慢—快"的变化趋势,根系的年分解率分别为64%、56%和58%。3种草地根系完全分解（分解率为95%）时,分别需要1174天、1351天和1878天。随石漠化程度的加剧,3种草地的根系周转速率呈逐渐降低的趋势,分别为1.70次/a、1.36次/a和0.87次/a。

为了解油杉河牧场建立对植被动态的影响,给研究区畜牧业的可持续发展和草地资源的开发利用提供科学依据,以贵州省油杉河牧场为研究区域,将野外实地测量21个样方的覆盖度与每个采样点的7种植被指数(NDVI,DVI,RVI,EVI,SAVI,GVI,OSAVI)建立相对应回归模型,比较每种植被指数与覆盖度之间的相关性,然后选择最佳覆盖度估算模型估算研究区近30年覆盖度,定量分析年际覆盖度变化的特征,探讨了研究区覆盖度与气象因子的相关性.结果 表明,所建估算模型中线性模型和二次多项式模型相关性高于其他模型,其中植被指数SAVI的二次多项式模型精度高达90.27％,说明该模型具有可行性;1993年～2019年油杉河牧场覆盖度整体呈上升趋势,2006年和2015年上升幅度最大;近30年研究区覆盖度在月际水平上与温度、降水的相关性随着人类活动的增加呈逐渐减小趋势,牧场建立以后相关性不显著.人类活动对油杉河牧场植被覆盖度具有深远影响,推荐植被指数SAVI估算温暖湿润地区的人工草地覆盖度.

[目的]缓解多年生黑麦草的越夏问题,筛选优良的耐热品种.[方法]以多年生黑麦草3个牧用型品种麦迪、纽依和雅晴为研究对象,进行高温处理,通过测定其萌发与幼苗特性,研究高温胁迫对其种苗特性的影响.[结果]在高温胁迫下,各品种相对发芽率、相对发芽指数、相对活力指数、相对根苗长等指标总体上均呈下降趋势.结合各指标综合评定,3种多年生黑麦草在高温胁迫下的耐热性从强到弱依次为麦迪、纽依、雅晴.[结论]该研究可为获得高耐热性的多年生黑麦草品种提供理论指导.

The germination characters of chicory (Cichorium intybus L.)seeds were observed in this study.The result showed that with increase of aluminum ions contention,the germination rate and germination potential of chicory seeds have declined 2.05％-10.24％ and 3.43％ 12.03％ respectively compared with the controls.The seminal roots was inhibited under aluminum ions treatments,and the seminal roots has stop growing when the aluminum ions contention increased to 200 mg/L.The root resistance index was declined exponentially (y =239.26 e0.827x,R2 =0.942 3) with the aluminum ions contention increasing,the seminal seedling and seminal roots were positive correlation (R=0.900 8,p＜0.05).The result indicated that the chicory has poorer tolerance to aluminum stress,so that aluminum-tolerance cultivar should be selected in production of acid soil region with high aluminum.

Soil quality of natural grassland,cropland and pasture in the Karst mountain area of Guizhou was compared in the study.The results showed that there were significant difference of soil physical,chemical and effective micronutrient of natural grassland,cropland and the pasture in Karst mountain region.The BD,porosity and capillary water holding in soil of study area showed better pasture than natural grassland,and cropland was the worst.The soil of study area was high-acid,pH and between 3.49~4.44.And the pH of pasture and cropland soil was higher than natural grassland.The organic matter and total nitrogen in pasture soil were better than cropland and natural grassland.The available nitrogen,available phosphorus and available potassium in natural grassland were lower than pasture and cropland.The density of available iron,zinc and boron in 0 to 50 centimeter soil was natural grassland > cropland > pasture.The density of available copper and molybdenum in 0 to 50 centimeter soil was cropland > natural grassland > pasture.The density of available manganese in 0 to 50 centimeter soil was cropland > pasture > natural grassland.

Based on the determination of nutritive componenfs of Sophora viciifolia,the content of crude protein is 33.63%~37.37% and the content of crude fat is 2.50%~3.89% in leaves of dry matter of Sophora Viciifolia.Content of crude protein and crude fat is more lower in stems dry matter of Sophora viciifolia than in leaves of dry matter,It is respectively 28.38%~33.48% and 1.90%~2.68%.There are also a variety of vitamins in Sophora Viciifolia stems and soft leaves,such as vitamin C,β-carotene and vitamin D3,etc,but there are not vitamin B1 and vitamin E.Concerning the amino acid content,the total amino acid content is 10.28%~18.96% in leaves of dry matter.Essential amino acids to total amino acid in Leaf dry matter,the highest percentage is 37.29% in April.The results indicated that there are abundant nutrients in stems and soft Leaves,and Sophora Viciifolia has high feeding value.

乳酸杆菌能抑制肠道致病菌的生长繁殖,维持肠道菌群的平衡,降低仔猪发病率。综述了乳酸杆菌对仔猪肠道菌群的影响以及影响乳酸杆菌制剂使用效果的因素,为乳酸杆菌在仔猪生产中的合理应用提供参考。

盘县是贵州省种草养羊大县之一,通过在该县红果镇的挪弯村、纸厂村,淤泥乡的清水村、嘿白村、岩博村,保基乡的厨子寨村等地实施免耕技术建植人工草地866.67 hm2,均获成功.现将该技术报道如下.1免耕技术的优点(1)降低土壤呼吸强度,增加土壤有机质含量.(2)增加水稳性和土壤团粒结构的数量,提高土壤抗水蚀及风蚀的能力.(3)增加土壤的渗透性,减少地表径流,提高土壤的蓄水能力和水分利用效率.(4)提高土壤的生物活性.(5)减少劳动强度、时间和费用.(6)不受地形地貌及农机具限制,实施地点可为天然荒山草坡.

通过对特高、杰威、蓝天堂3个多花黑麦草品种的营养成分和细胞壁各物质含量在品种和茬次间的比较，结果表明，品种因素影响着多花黑麦草的营养价值及适口性，3个品种的品质以杰威最优，特高次之，蓝天堂最差；茬次对多花黑麦草的营养成分及细胞壁各物质含量有明显影响，表现为各品种的粗灰分、ADF和ADF含量随刈割茬次的增加而增加，而粗蛋白则随刈割茬次的增加而降低。

Transplanting densities were studied on density and biomass of Trifolium repens,sifting the adaptive transplanting density in order to providing guidance for ecological stock rising in China.Experimental design is set up with six transplanting densities and six mowing times.Density and biomass were measured when average height was 20 cm.Results indicate that both fresh and dry biomass of white clover significantly increase with transplanting density increasing in early stage(P0.01),but increasing rate decreases with increased mowing.For middle stage,neither fresh biomass nor dry biomass is significantly changed.For the 6th mowing,biomass of white clover significantly changes between different transplanting density(P0.05).The total biomass increases as transplanting density increasing.Results show that the 49 plum·m-2 is suitable transplanting density for producing high biomass yield.

研究以植物乳杆菌(Lactobacillus plantarum)为目标菌株,对冷冻干燥高活力乳酸菌粉的保护剂和保存条件进行了试验。结果表明:①海藻糖、谷氨酸钠、蔗糖、山梨醇和乳糖等5种保护剂对植物乳杆菌在冷冻干燥和干燥后贮存过程中均有显著的保护作用,其中,海藻糖的保护作用最为显著,植物乳杆菌存活率高达78.90%,而蔗糖、谷氨酸钠、乳糖和山梨醇作用稍差;②添加了不同保护剂制得的植物乳杆菌粉在4℃和25℃条件下的贮存结果表明,随着贮存温度的升高,植物乳杆菌的死亡率增加,随着保存时间的延长植物乳杆菌的死亡速度加快,添加海藻糖可以明显减缓植物乳杆菌的死亡速度。

乳酸菌具有补充、调整或维持动物肠道内的微生态平衡,达到防治疾病、促进健康和提高生产性能的作用。介绍了乳酸菌添加剂在畜牧业上利用的作用机理,总结了作为青贮添加剂的作用效果研究以及直接饲喂动物的效果,最后提出了乳酸菌在畜牧业上的研究方向。

为了给白三叶草的选育和资源利用提供理论依据,采用聚丙烯酰胺凝胶电泳的方法,对来自不同地区的16份白三叶草(Trifolium repens L.)种质资源进行酯酶(EST)和过氧化物酶(POD)同工酶检测,并对检测到的5个等位酶位点的图谱进行分析,再根据各种质资源间遗传相似度及聚类结果进行分析.结果表明:白三叶草各种质资源间有较高的遗传多样性;16份白三叶草种质资源在相似系数为0.71的水平上可以聚为三类,大部分地理区域临近的种质材料首先聚在一起.说明他们有较近的亲缘关系.

Because seed of Sophora viciifolia is very hard,the seeds should be treated with suitable methods to improve its permeability of seed coat and seed germination rate.The seeds of Sophora viciifolia were treated with 98% sulphuric acid,hot water and mechanical abrasion with coarse sand methods to study the effect on germination rate of Sophora viciifolia seeds.The results showed that three treatment methods all had the breaking effect on Sophora viciifolia seeds,the germination rate of Sophora viciifolia seeds soaked in 98% sulphuric acid,for 25min was 66.6%,the germination rate of Sophora viciifolia seeds soaked in hot water was 54.4% and the germination rate of Sophora viciifolia seeds treated with coarse sand was 31.8%.The hot water treatment method should be used in seed germination improvement of Sophora viciifolia because a large number of Sophora viciifolia seeds can be easily treated.

The results from studying the effects of different mowing intensity on growth characteristic and biomass of Trifolium repens,showed that the different stubble height had the significant effects on branching number,creeping stem length and biomass of Trifolium repens.The first and second branch number of the stubble with 1 cm height was 20.33 and 50.30 branches/plant,and the first and second branch number of the stubble with 3 cm height was 18.40 and 43.17 branches/plant respectively.The third branch number of the stubble with 3 cm was the highest(21.37 branches/plant).The creeping stem length decreased with increase of mowing intensity and the aerial biomass presented the trend of first increase and then decrease with reduction of stubble height,which indicates that the higher and lower stubble height all reduces its yield.The stubble with 3 cm is beneficial to growth and biomass of Trifolium repens.

Under a particular landscape and climate conditions of Guizhou,The reproductive period of three Italian ryegrasses is Up to 250 days or more which is autumn sowing,so they are in late-maturing varieties;their Tillers were "S" increasing completly,Tetragold and Blueheaven were stronger than Splendor;But tillering ability is most at 1.5g/m2 and 2.0g/m2;moreover,Species×density interaction effect and Stubble times have obvious influence and promote the role on tiller.It provides a theoretical basis and technical guidance about Scientifically plant and use of Italian ryegrass,as well as it is conducive to better promote and use of Italian ryegrass in Gui zhou province.

高羊茅在我国有着广泛的种植面积,是多年生冷季型牧草和草坪草.介绍了高羊茅的再生体系,从它的转化方法、转化目标、影响因素、生物安全问题等方面综述了高羊茅的外源基因转化研究进展.

The regression equation,y=-1.846 7+0.337x1+1.970 5x2-0.568x3+0.629 2x4,for calculating the leaf area and relative indexes of Trifolium repens was established by using its leaf length and leaf width as measuring indexes.The results showed that there was a very significant linear correlation between the regression equation and measuring indexes and its correlation coefficient was up to 0.987 3.The mathematical model with the simple and practical advantage can be easily used in measuring leaf area of Trifolium repens.