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11.
长期秸秆还田显著降低褐土底层有机碳储量 总被引：2，自引：0，他引：2
12.
Zhou Xiaoyang Wang Boren Cai Zejiang Colinet Gilles 《Communications in Soil Science and Plant Analysis》2018,49(7):791-802
Phosphorus (P) deficiency is one of the main problems limiting crop growth in red soils of southern China. The primary objective of this study was to examine P availability as a function of soil acidity. Soils were sampled from a long-term fertilization experiment and are referred as low-P (No P fertilization) and high-P (120 kg P2O5 ha–1). Both low-P and high-P treatments were incubated adjusting soil pH to seven levels from 3.0 to 6.5 for 10, 20, 30 and 45 days. The pH, DIP, and Olsen-P were determined after each incubation period, and inorganic P fractions were measured at the end of incubation. For both low-P and high-P treatments, DIP decreased with rising pH value and increased with decreasing soil pH. Olsen-P, Ca-P (Ca2-P, Ca8-P, and Ca10-P) and Al-P increased significantly with soil pH in low-P treatment. In high-P, Olsen-P increased with pH between 3.4 and 5.0 and was stable at higher pH. Moreover, Ca-P and Al-P increased significantly but Fe-P decreased with soil pH increase. The redundancy analysis showed that Ca-P, Al-P, and pH had positive effects on Olsen-P, but Occluded-P showed a negative correlation with Olsen-P in both soils. Our results confirmed that soil P availability was influenced by pH and that the changes in DIP and Olsen-P were linked to changes of inorganic fractions from occluded to Ca- and Al-bound forms. Managing soil acidity is a key issue regarding the availability of P in red soils of China and our results suggest that at least a pH of 5.0 should be targeted. 相似文献
13.
Yanqun Zu Laurent Bock Christian Schvartz Gilles Colinet 《Archives of Agronomy and Soil Science》2013,59(1):107-117
Chinese cabbage and surface soil samples (0–20 cm) from a periurban market garden in Yunnan Province (P.R. China) were collected to determine variations of cadmium (Cd) and zinc (Zn) contents in Chinese cabbage and the influence of soil factors. Mean Cd content was 0.49 mg kg?1 dry materials (DM) in Chinese cabbage, ranging between 0.23 and 1.34 mg kg?1 DM (n = 21 samples). Mean Zn content was 51.2 mg kg?1 DM, ranging from 34.9 to 157.5 mg kg?1 DM (n = 21 samples). The soil factors best predicting Chinese cabbage Cd and Zn contents were total and available Cd and Zn contents and cation exchange capacity (CEC). Soil samples and corresponding Chinese cabbage samples were divided into two groups: soils with low pH (<6.5, n = 10) and soils with high pH (>6.5, n = 11). Positive correlation between CEC with pH > 6.5 and Cd and Zn contents in Chinese cabbage were observed. Available trace element contents and CEC explained 77% and 69% of variation of Cd and Zn contents in Chinese cabbage, respectively. AEC (enrichment coefficient related to trace element availability) and BCF (bioaccumulation factors) could be used to understand Cd and Zn accumulation in Chinese cabbage. 相似文献
14.
Rodrigo R. Mota Sylvie Vanderick Frdric G. Colinet Hedi Hammami George R. Wiggans Nicolas Gengler 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2019,136(6):430-440
Recent publications indicate that single‐step models are suitable to estimate breeding values, dominance deviations and total genetic values with acceptable quality. Additive single‐step methods implicitly extend known number of allele information from genotyped to non‐genotyped animals. This theory is well derived in an additive setting. It was recently shown, at least empirically, that this basic strategy can be extended to dominance with reasonable prediction quality. Our study addressed two additional issues. It illustrated the theoretical basis for extension and validated genomic predictions to dominance based on single‐step genomic best linear unbiased prediction theory. This development was then extended to include inbreeding into dominance relationships, which is a currently not yet solved issue. Different parametrizations of dominance relationship matrices were proposed. Five dominance single‐step inverse matrices were tested and described as C1 , C2 , C3 , C4 and C5 . Genotypes were simulated for a real pig population (n = 11,943 animals). In order to avoid any confounding issues with additive effects, pseudo‐records including only dominance deviations and residuals were simulated. SNP effects of heterozygous genotypes were summed up to generate true dominance deviations. We added random noise to those values and used them as phenotypes. Accuracy was defined as correlation between true and predicted dominance deviations. We conducted five replicates and estimated accuracies in three sets: between all ( S1 ), non‐genotyped ( S2 ) and inbred non‐genotyped ( S3 ) animals. Potential bias was assessed by regressing true dominance deviations on predicted values. Matrices accounting for inbreeding ( C3 , C4 and C5 ) best fit. Accuracies were on average 0.77, 0.40 and 0.46 in S1 , S2 and S3 , respectively. In addition, C3 , C4 and C5 scenarios have shown better accuracies than C1 and C2 , and dominance deviations were less biased. Better matrix compatibility (accuracy and bias) was observed by re‐scaling diagonal elements to 1 minus the inbreeding coefficient ( C5 ). 相似文献
15.
Des 1980, la résistance aux imides cycliques (I. C.) s'est généralisée dans les populations de Botrytis cinerea sur fraisiers remontants, traités de 3 à 10 fois de juillet à septembre avec des I. C., le taux moyen de fraises présentant des conidies résistantes étant de 72%. Une diminution progressive du taux de résistance est observée après l'arrêt des traitements, mais est suivie d'une forte augmentation 5 à 6 semaines apres la reprise des traitements l'année suivante. L'efficacité des traitements à la vinchlozoline (500 g ha?1) est passée de 94%, pour les essais de 1973 à 1978, à 48% pour ceux établis de 1979 à 1984. Durant cette derniére période, le mélange vinchlozoline (500 g ha?1)+ thirame (1600 g ha?1) a présenté une efficacité de 78% et le tolylfluanide a donné une efficacité de 67%. Sur fraisiers de saison, traités 1 à 6 fois au moment de la floraison, une résistance aux I. C. a été observée en 1980 dans sept des 10 champs analysés, avec un taux moyen de 22%. La résistance ne s'y développe que tardivement et principalement dans les cultures de 2 ans, traitées déjà l'année précédente avec des I. C. Dans les essais, l'efficacité de la vinchlozoline s'est maintenue á 92% entre 1973 et 1984. 相似文献
16.
中国南方水稻土酸化演变特征及影响因素 总被引：17，自引：1，他引：16
【目的】明确中国南方水稻土酸化特征及主要影响因素,为防控水稻土酸化提供理论依据。【方法】选择中国南方江苏、湖南、广东、广西、四川和云南6个省份（自治区）的20个水稻土长期定位监测点,统计分析水稻土pH演变特征及阶段性变化规律,并探讨施肥量及土壤氮素含量对水稻土酸化的影响。【结果】1988-2013年25年间中国南方水稻土显著酸化,土壤pH下降0.59个单位,平均每年下降0.023个单位。水稻土酸化具有明显的阶段性特征,起始的14年中水稻土pH急速下降,平均每年可下降0.051个单位;近10年间,土壤pH趋于平稳。增施化肥特别是化学氮肥可导致水稻土酸化,二者与土壤pH均呈显著负相关关系（P＜0.01）,由此推算出化学氮肥每增施100 kg·hm-2,水稻土pH可下降0.65个单位。减少有机肥的施用也可引起水稻土酸化,有机肥施用量与土壤pH之间呈显著正相关关系,有机肥每减少100 kg·hm-2,水稻土pH下降0.51个单位。土壤全氮及碱解氮含量与pH间均呈极显著负相关关系,土壤全氮和碱解氮含量每增加100 mg·kg-1,水稻土pH约下降0.1个单位。【结论】在过去25年间,中国南方水稻土显著酸化,酸化具有明显的阶段性特征,施肥初期土壤pH显著降低。减少化学氮肥的施用和增施有机肥是控制水稻土酸化的重要措施。 相似文献