保山市冬早大棚辣椒氮磷钾肥料优化施用

针对保山区域冬早大棚辣椒氮磷钾肥料效应缺乏系统研究,存在偏施氮肥、盲目施肥和过量施肥的现象,采用三因素五水平二次正交旋转组合设计,通过田间小区试验,研究氮磷钾肥料效应模型,通过频率分析研究高产优化施肥组合方案。保山大棚辣椒氮磷钾肥料效应回归模型Y=38 180.4+19.865 7N+16.102 7P+16.150 1K+0.026 6NP+0.012 4NK-0.006 8PK-0.025 8N~2-0.038 5P~2-0.014 1K~2,目标产量大于53 000kg/hm~2的优化施肥组合方案为N 568.9~631.9 kg/hm~2,P_2O_5 242.7~321.3 kg/hm~2,K_2O 684.6~794.8 kg/hm~2,氮磷钾比例为1∶0.47∶1.23,与当地施肥量水平相比,温暖区氮肥用量平均降低36.3%,温热区氮肥用量平均降低23.1%。氮磷钾肥配合施用能显著提高大棚辣椒产量,氮肥效应达极显著水平,磷肥和钾肥效应达显著水平,效应排序为氮肥钾肥磷肥;氮磷和氮钾的交互效应为显著正效应,N用量在175~425 kg/hm~2时,辣椒产量随着P_2O_5用量的增加呈先增后降趋势,增幅随着磷肥用量的增加而减小,N用量在175~573.7 kg/hm~2时,钾肥效应趋势与磷肥一致,在高氮情况下,辣椒产量随着磷肥(或钾肥)用量的增加而增加。     

应用最优混合设计研究氮磷钾不同配比对甘蔗产量和产糖量的效应

应用“311—A”最优混合设计进行田间试验,研究氮肥、磷肥、钾肥用量不同配比对甘蔗产量和产糖量的效应,通过运用统计分析软件对试验结果进行回归分析,建立多项式回归模型,寻求出甘蔗蔗茎产量及其产糖量的氮肥、磷肥、钾肥最佳组合范围及其最佳配比用量方案。在供试条件下,对于甘蔗产量的氮、磷、钾肥料用量最佳组合范围方案为:N=268.6~312.2kg/hm2,P2O5=130.7~141.3kg/hm2,K2O=322.4~344.8kg/hm2,N∶P2O5∶K2O=1∶0.45~0.49∶1.10~1.20,最高产量预测值为112.7t/hm2;对于产糖量的最佳组合范围方案为:N=257.9~290.8kg/hm2,P2O5=139.0~158.0kg/hm2,K2O=325.3~350.6kg/hm2,N∶P2O5∶K2O=1∶0.54∶1.20~1.26,最高产糖量预测值为16.3t/hm2。对于产量的经济最佳施肥量方案为:N=311.7kg/hm2,P2O5=140.8kg/hm2,K2O=344.4kg/hm2,N∶P2O5∶K2O=1∶0.45∶1.10;对于产糖量的经济最佳施肥量方案为:N=290.6kg/hm2,P2O5=157.8kg/hm2,K2O=350.4kg/hm2,N∶P2O5∶K2O=1∶0.54∶1.21。     

膜荚黄芪氮磷钾优化施肥模式研究

采用氮,磷,钾三因素二次D-饱和最优设计,通过田间试验,建立了氮磷钾的施肥量编码值与膜荚黄芪根产量、多糖含量的效应函数。结果表明,氮、磷、钾肥对膜荚黄芪根产量的增产作用大小依次为:氮肥＞钾肥＞磷肥;氮、磷、钾肥对黄芪多糖含量的作用大小依次为:钾肥＞磷肥＞氮肥,其中钾肥为负效应,氮肥、磷肥为正效应。寻优结果表明,膜荚黄芪目标产量在6000～7000 kg/hm2之间,95%置信区间的优化施肥量为:N 66.85～102.92 kg/hm2,P2O5 64.64～94.95 kg/hm2,K2O 119.78～166.48 kg/hm2;膜荚黄芪多糖含量在13%～14%之间,95%置信区间的优化施肥量为:N 66.85～102.92 kg/hm2,P2O5 64.64～94.95 kg/hm2,K2O 119.78～166.48 kg/hm2;膜荚黄芪高产优质高效栽培优化施肥量为:N 99.52～102.92 kg/hm2,P2O5 94.20～94.95 kg/hm2,K2O 119.78～166.48 kg/hm2,N、P2O5、K2O的最佳比例为:1: 0.92～0.95:1.16～1.62。     

优质稻肥料效应试验

为取得有关施肥参数,建立优质稻施肥模型,选择高、中、低肥力田块,应用3因素4水平设计方案对优质稻进行田间肥效试验。结果表明,在一定范围内氮、磷、钾肥的施用对优质稻的增产作用是氮肥大于磷肥,磷肥大于钾肥,建议梁河县优质稻高肥力田块氮、磷、钾施用量分别为N 73 kg/hm2、P2O535.6 kg/hm2、K2O87.8 kg/hm2,应施好氮、磷肥,增施钾肥。中肥力、低肥力田块氮、磷、钾施用量分别为N 87.48～103.7 kg/hm2、P2O559～63 kg/hm2、K2O 47.6～52 kg/hm2,应增施氮肥、磷肥,适量钾肥。     

杂交酸模优化施肥的数学模型及解析

采用二次正交回归旋转组合设计,所建立的杂交酸模优化施肥数学模型达到极显著水平.氮肥、磷肥、钾肥对杂交酸模生物量的影响均十分显著,钙肥的作用仅次于磷肥,氮、磷配合施用可使杂交酸模生物量显著增加,而增施氮肥是增产的关键.通过产量频数法分析,杂交酸模生物量≥55000kg/hm2的优化施肥方案为氮肥(N)186～210kg/hm2,磷肥(P2O5)125～135kgg/hm2,钾肥(K2O)65～73kg/hm2,锌肥(ZnSO0)60～70kg/hm2,钙肥(Ca(NO3)2)61～68kg/hm2.     

桔梗氮、磷、钾施肥效应与施肥模式研究

采用氮、磷、钾三因素2次D-饱和最优设计(310),通过大田试验建立了氮、磷、钾施肥量与桔梗产量和总皂苷含量的效应函数。结果表明,氮、磷、钾肥对桔梗产量的影响大小依次为氮肥 钾肥 磷肥;氮、磷、钾肥对桔梗总皂苷含量的影响大小依次为氮肥 磷肥 钾肥。对各效应函数进行频率分析法寻优结果表明,桔梗目标产量在4200～4800 kg/hm2,95%置信区间的优化施肥量为N 83.72～119.41 kg/hm2、P2O5 64.10～134.39 kg/hm2、K2O 78.80～147.20 kg/hm2;桔梗总皂苷含量在5.5%以上,95%置信区间的优化施肥量为N 113.37～140.12 kg/hm2、P2O5 85.96～153.44 kg/hm2、K2O 76.86～136.38 kg/hm2;桔梗高产优质高效栽培最优施肥量为N 113.37～119.41 kg/hm2、P2O5 85.96～134.39 kg/hm2、K2O 78.80～136.38 kg/hm2,N、P2O5、K2O的最优施用量配比为1︰0.72～1.18︰0.66～1.20。     

结球甘蓝平衡施用氮磷钾肥效应研究

应用311-A拟饱和最优回归设计和{3,2}单形格子饱和设计,通过氮磷钾肥配比和氮肥分期施用田间试验,建立结球甘蓝施用氮磷钾肥对经济产量、施肥利润及氮肥分期施用比例的效应函数。寻优结果表明,结球甘蓝最高产量的氮、磷、钾优化施肥组合为N277.83、P2O5.64.59和K2O126.53kg.hm2,其最高经济产量达73.877t.hm2;最佳施肥利润的氮、磷、钾优化施肥组合为N267.15、P2O5.62.63和K2O121.56kg.hm2,其最佳施肥利润达46085.87元.hm2,经济产量为73.786t.hm2;较佳施氮分配比例为基肥∶前期追肥∶后期追肥为0.3840∶0.3554∶0.2606,其对应的氮肥用量分别为N106.75、98.80和72.45kg.hm2,期望较高的经济产量可达74.946t.hm2。     

氮磷钾配施对洋葱产量和品质的影响

采用三因子二次饱和D-最优设计(310),研究了氮磷钾配施对洋葱产量和品质的影响,建立了以氮、磷、钾施用量为变量因子,洋葱产量及品质为目标函数的三元二次数学模型。通过对模型解析表明,氮、磷、钾肥对洋葱产量和品质均有显著影响,且均以磷肥的影响最大,氮肥次之,钾肥较小;当氮、磷、钾肥用量分别达430.7、449.5和1152.7 kg/hm2时,边际产量效应值降至 0。氮磷、氮钾交互对洋葱的产量也有显著影响,其互作效应最显著的区域为N 240.0～720.0 kg/hm2、P2O5 250.0～500.0 kg/hm2、K2O 600.0～1500.0 kg/hm2。本试验条件下,洋葱产量达 75 t/hm2、品质综合评分达90分以上的综合施肥方案为:N 294.0～480.6 kg/hm2、P2O5 332.8～388.5 kg/hm2、K2O 861.8～1119.8 kg/hm2,适宜的 N、P2O5、K2O施用比例约为1∶0.93∶2.56。     

旱地辣椒栽培中密度、氮、磷及钾肥因子的优化

采用四因素二次正交旋转组合试验设计,研究了旱地辣椒双垄沟全膜覆盖育苗移栽条件下密度、氮肥、磷肥、钾肥对辣椒产量的影响.试验结果单因子效应分析表明,随着栽培密度、施氮量和施磷量的提高,辣椒产量呈先升后降的趋势;随着施钾量的提高,辣椒产量呈上升趋势.双因素交互效应分析表明,栽培密度与施钾量之间存在互作效应.获得旱地辣椒产量45 000.00 kg/hm2以上的栽培密度和氮磷钾优化方案为:密度49 071 ～ 52 179穴/hm2,每穴移栽2株,施N量216.75 ～ 257.25 kg/hm2,施P2O5量234.45 ～ 257.55 kg/hm2,施K2O量141.45 ～ 158.10 kg/hm2,适宜的N∶P2O5∶K2O为1.6∶1.6∶1.0.验证试验结果表明,优化栽培较常规栽培增产26.6％ ～ 41.3％.     

芝麻氮、磷、钾肥的效应研究

为探明芝麻生产中氮、磷、钾肥最优化施肥参数,本试验运用“3414”肥料效应田间试验方案,对白芝麻品种郑芝98N09和黑芝麻品种冀9014的氮、磷、钾肥料效应进行了研究.结果表明:适量氮、磷、钾用量及其配施能显著改善芝麻的经济性状,提高芝麻产量.施氮量与芝麻株高、单株蒴数、单蒴粒数、千粒重等经济性状呈显著正相关,氮、磷、钾肥对郑芝98N09的经济性状的影响为氮＞磷＞钾,冀9014为氮＞钾＞磷.通过建立肥料与产量效应函数方程并结合经济效益分析得出,郑芝98N09的最佳施肥量为N 123.09 kg/hm2、P2O5 60.13 kg/hm2、K2O 73.31 kg/hm2,冀9014的最佳施肥量为N 133.92 kg/hm2、P2O5 70.85 kg/hm2、K2O 110.80 kg/hm2.因此,郑芝98 N09施肥时应重施氮肥,适配磷、钾肥;冀9014应重施氮、钾肥,兼施磷肥.     

“绿色革命”以来大气CO2浓度升高对C3作物营养品质的影响

自20世纪60年代"绿色革命"以来,育种技术和农耕技术的发展促进了农作物产量的大幅提升,然而作物的营养品质出现下降趋势。在相似的遗传背景下,大气CO_2浓度升高会使单位体积农作物产品的营养元素含量下降,因此"绿色革命"至今,农作物产品的营养元素下降可能受大气CO_2浓度升高影响。通过植物生长箱模拟"绿色革命"初期和目前的大气CO_2浓度水平(310μmol/mol和400μmol/mol),针对主要C_3作物水稻、小麦和大豆,研究"绿色革命"以来大气CO_2浓度升高对其籽粒的C、N、Fe、Zn元素含量的影响,结果表明:CO_2浓度升高对3种作物籽粒的C元素含量几乎没有影响,变化幅度在±1.5%之间;籽粒的N、Fe、Zn元素含量普遍呈现下降趋势,但均未达到显著水平。     

Potential of wild species for genetic enhancement of some semi-arid food crops

Discovery and incorporation of genes from wild species provide means to sustain crop improvement, particularly when levels of resistance in the cultigens are low and virulent strains of pests and pathogens overcome the host plant resistance. The extent of utilization and the potential of the wild genepool for genetic enhancement were reviewed in five important food crops viz. sorghum, pearl millet, chickpea, pigeonpea and groundnut grown in the semi-arid tropics. Introgression from compatible wild germplasm in the primary gene pool resulted in transfer of new cytoplasmic male sterility systems in pearl millet and pigeonpea, development of high protein, cleistogamous flower and dwarf pigeonpea lines and foliar disease resistant groundnut cultivars. Utilization of wild species in secondary and tertiary gene pools has been generally limited due to sterility, restricted recombination or cross incompatibility. Nevertheless, these species are extremely important as they contain high levels of resistance to several important biotic and abiotic stresses. Several of them, like those belonging to the Parasorghum section and the rhizomatous Arachis species are sources of multiple resistances and hold great promise to sustain crop productivity.     

Faculty positions:Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.     

Enhanced establishment and growth of giant cardon cactus in an eroded field in the Sonoran Desert using native legume trees as nurse plants aided by plant growth-promoting microorganisms and compost

To evaluate the feasibility of long-term desert reforestation technology of mixed vegetation, cardon cactus (Pachycereus pringlei) seedlings from indoor and outdoor nurseries were planted in the field adjacent to one seedling of potential legume nurse trees: mesquite amargo (Prosopis articulata), yellow palo verde (Parkinsonia microphylla), and blue palo verde (Parkinsonia florida). Some of the planting holes were also supplemented with common dairy compost. Additionally, the combinations of legume tree–cactus were inoculated with either a consortium of desert arbuscular mycorrhizal (AM) fungi, plant growth promoting bacteria (PGPB; the diazotroph Azospirillum brasilense Cd, and the phosphate solubilizer Paenibacillus sp.), or a mixture of all. The field experiments were evaluated periodically during 30 months for survival and growth. Cardons reared in an outdoor screen house survived better in the field than those reared in a controlled growth chamber and hardened later outdoors. Association with any legume nurse tree increased survival and enhanced growth of untreated cardons. For cardons growing alone, application of either compost, AM fungi, and all the treatments combined increased survival. For these plants, no treatment affected plant growth during the first 3 months after transplanting. Later, all treatments, except for AM fungi, enhanced plant growth. However, only 2 years after transplanting the enhanced growth effect of AM fungi was also significant. In the presence of the legume nurse trees, transient positive effects on cardon growth were recorded. General evaluation after 30 months of cultivation showed that the treatments positively affected cardon growth when growing alone or in combination only with mesquite amargo but not with the other two legume trees. This study proposes that young legume trees have the capacity to enhance survival and growth of cardon cactus, depending on the legume cactus combination. Additional treatments such as compost or PGPB can either amplify the effect or else attenuate it.     

Collection and preliminary evaluation of native turfgrass accessions in Italy

Despite a raising interest on turfs in Italy, all theavailable varieties of this kind in the Country are of foreign origin, and areoften poorly adapted to the prevailing climatic conditions. This prompted tobegin a collection activity of indigenous turfgrass species, with the ultimategoal of identifying promising materials for future breeding based on localgenetic resources. The collection was carried out in three areas of Italy, viz.the northern Po Plain, the coastal region of Liguria, and the island of Sardiniathat are characterised, respectively, by subcontinental, warm temperate, andtypical Mediterranean climate. Altogether, 141 sites were visited, yielding 226accessions belonging to eight species of potential interest for turfs:Poa pratensis, Poa trivialis,Festuca rubra, Festuca arundinacea,Lolium perenne, Agrostis stolonifera,Agrostis tenuis, and Cynodon dactylon,this last being a warm-season grass. Poa pratensis andCynodon dactylon were mostly collected in northern Italyand Sardinia, respectively, whereas Festuca arundinacea andLolium perenne were rather ubiquitous. The collection sitesranged from 0 to 1040 m asl, but sites over 750 m wereonly visited in the inner part of Sardinia. All the accessions, collected aswhole plants, were transplanted at Lodi, northern Italy, where they are beingevaluated. Their preliminary evaluation for traits of importance for turf use,such as sward colour and overall quality, highlighted the great variation andthe occurrence of interesting accessions in all species. Other characters wererecorded, bearing specific importance in individual species, and in all casespromising accessions were identified. The germplasm of Festucarubra, Festuca arundinacea, and Loliumperenne proved highly infected by endophytic (symbiotic) fungi of thegenus Neotyphodium.     

Karyotypic and genome size variation in Cajanus cajan (L.) Millsp. (pigeonpea) and some wild relatives

Detailed karyotypes and 4C DNA amounts have been studied in five cultivars of Cajanus cajan and 20 species belonging to Cajanus, Rhynchosia, Dunbaria, Flemingia and Paracalyx. C. cajan shows intraspecific variability and its karyotype is most similar to that of C. cajanifolius (sect. Cajanus) in the morphology and number of satellite chromosomes and the lack of any correlation between chromosome size within the complement and asymmetry. Karyotypes of C. lineatus and C. sericeus belonging to sect. Atylia are similar with respect to maximum r-index and the ratio of longest and shortest chromosomes in their respective complements. C. acutifolius (sect. Frutocosa) is distinct in having a very low ratio (1.44) between the longest and the shortest chromosomes, while in C. albicans, C. goensis, C. scarabaeoides (sect. Cantharospermum) there is no chromosome pair with r-index >2.0. C. mollis and C. volubilis (sect. Volubilis) show similarity with regard to ratio between the longest and the shortest chromosomes and a distinct chromosome pair with an arm ratio of 2.7 and C. platycarpus is distinct (sect. Rhynchosoides) in having the smallest ratio (1.36) between the longest and the shortest chromosomes. 4C DNA amounts in Cajanus and Rhynchosia vary between 3.28 pg to 11.69 pg and 4.92 pg to 11.13 pg respectively, while in Dunbaria, Flemingia and Paracalyx these vary between 4.70 and 7:06 pg. In the genus Cajanus karyotypic features and 4C DNA amounts agree with the sectional classification and bring out a close relationship between C. cajan and C. cajanifolius. This is supported by studies based on seed protein patterns, isozyme analysis, trypsin and chymotrypsin inhibitor patterns, RFLP and RAPD data and crossability relationships. A clear relation between DNA amount and abnormalities effecting the extent of pairing and recombination in interspecific hybrids shows the importance of this study in developing future breeding programme involving C. cajan and its wild relatives that are of potential value.     

Effect of some fungicide seed treatments on the survival of Bradyrhizobium japonicum and on the nodulation and yield of soybean [Glycine max. (L) Merr.]

Several commercial fungicide seed treatments were evaluated for their possible effect on the survival of Bradyrhizobium japonicum on seeds and on the nodulation and yield of soybeans in a greenhouse and a field experiment. quinolate Pro (carbendazim and oxine copper), Vitavax 200FF (carboxin and thiram), and Monceren (pencycuron) had a small effect or no effect on the survival of B. japonicum and on the nodulation and yield of soybeans. They can thus be considered compatible with soybean seed inoculation. Germipro UFB (carbendazim and iprodione), Apron 35J (metalaxyl), and Tachigaren (hymexazol) decreased B. japonicum survival and the nodulation and yield of soybeans and thus cannot be considered compatible with soybean seed inoculation.     

Leaf position and genotype differences for mineral element concentrations in sorghum grown on tropical acid soil 1

Mineral element deficiencies and toxicities are common problems associated with sorghum [Sorghum bicolor (L.) Moench] production on acid soils. To better understand some of the mineral element problems and the analysis of plant tissue of sorghum plants grown on acid soils, four sorghum genotypes were grown on an acid Oxisol at Carimagua, Colombia limed with dolomite at 2 and 6 Mg ha^‐1.

Samples for mineral element analyses were obtained from leaves at different positions on the four genotypes. Concentrations of P and Mg were highest in the flag leaf (Leaf No. 1) and decreased as the position on the plant declined from the top of the plant for plants grown at 2 Mg lime ha^‐1. Similar decreases in P, Mg, K, and Zn concentrations occurred in plants grown with 6 Mg lime ha^‐1. Concentrations of Ca, S, Si, Mn, Fe, Cu, and Al increased as leaf position declined from the flag leaf for plants grown at 2 and 6 Mg lime ha^‐1. The higher lime supply enhanced Ca and reduced Mn and Fe concentrations in leaves. Differences in mineral element concentrations for the four genotypes used were fairly extensive. The elements to show the greatest range among genotypes were Al and Si and the elements to show the least range among genotypes were P, K, and S. Care should be used in collecting leaf samples for plant analysis and genotypic differences for accumulation of mineral elements should be considered in interpretation of results.