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61.
62.
S. C. Misra R. Randive V. S. Rao M. S. Sheshshayee R. Serraj P. Monneveux 《Journal of Agronomy and Crop Science》2006,192(5):352-362
Carbon isotope discrimination (Δ) and ash content (ma) have been proposed as indirect selection criteria for grain yield in wheat. The associations between Δ, ma and grain yield were found, however, to depend highly on the environmental conditions, the organ sampled and the time of sampling. In this study, carried out in the warm conditions of the Peninsular Zone of India, the relationship between Δ, ma and yield was studied in 30 bread and durum wheat cultivars under residual soil moisture stress (RSMS), post‐anthesis water stress (PAWS) and well‐watered (WW) conditions. Both Δ and ma were analysed in young seedlings (four‐leaf stage), leaves at anthesis and grain at maturity. Ash content was also evaluated in leaves at booting stage and maturity. Grain Δ was lower under PAWS and RSMS than under WW, while seedling and leaf Δ did not significantly differ among water regimes. Grain yield was positively correlated to grain Δ under PAWS and negatively correlated to grain ma under RSMS. A significant positive correlation was noted under RSMS and WW treatments between maLm and grain yield. Ash content in leaf at maturity consequently appears to be a useful indirect selection criterion in environments where Δ does not show any correlation with yield. The results highlight the potential of Δ and ma as indirect selection criteria for wheat yield in the conditions of the Peninsular Zone of India. 相似文献
63.
安溪茶园土壤矿质元素质量分数与土壤母质关系较为密切．其中Ｋ、Ａｌ的质量分数是凝灰岩母质＞ 花岗岩母质＞ 第四纪红土母质;Ｆｅ、Ｍｎ、Ｚｎ 质量分数是凝灰岩母质＞ 第四纪红土母质＞ 花岗岩母质．土壤有效性的矿质元素与铁观音乌龙茶的生化品质存在着密切的相关．如土壤中的有效Ｚｎ,活性Ａｌ与速效Ｐ的比值与茶叶的氨基酸总量呈显著或极显著正相关;活性Ｍｎ 与茶多酚呈显著的正相关;速效Ｐ、活性Ｆｅ、活性Ｍｎ与水浸出物和总糖质量分数呈显著或极显著的正相关． 相似文献
64.
台江采育场竹木混交林丰产措施试验 总被引：1，自引：0，他引：1
对台江林业采育场现有竹木混交林进行施肥和土壤垦复两种试验,结果表明,不同施肥处理虽有一定增产效果,但经方差分析未达到显著水平;不同土壤垦复措施的增产效果,以深翻加施肥的新竹产量最高,锄草松土居第二,单纯深翻并不理想,效果不如劈山抚育。因而,新兴竹木混交林应以调整竹林结构和护笋养竹为主,每年锄草松土即可达到材用丰产林标准,不宜盲目深翻、施肥。 相似文献
65.
络合滴定黑荆栲胶中单宁含量的新方法 总被引：8，自引：0，他引：8
利用单宁分子结构中酚羟基能与Ｐｂ＾２＋络合的原理,以Ｋ２ＣｒＯ４为指示剂,ＰＡＭ作终点增敏剂,用Ｐｂ＾２＋标准溶液络合滴定黑荆栲胶中单宁的新方法。该法比皮粉法快速、准确。 相似文献
66.
The study examines vegetation – environment relationships. Vegetation measurements included species frequency, density, diameter and tree height, while environmental measurements were soil particle size distribution, acid properties (pH, Al, SO4), nutrient cations (Ca, Na, Mg, K), organic carbon, nitrogen, phosphorus and chloride content. Nypa fruticans was the dominant species in the A stratum (> 3 m tall) while Rhizophora mangle was dominant in the B stratum (1–3 m tall). The C stratum (< 1 m tall) was dominated by mangrove, Nypa and Raphia saplings. Silt was dominant and the most variable particle size fraction. A principal components analysis of the soil data indicated the first three dominant components influencing the vegetation were salinity, nutrient and soil texture. Tree height and density correlated highly with the salinity and soil texture gradients (P < 0.01), while basal area correlated with salinity and nutrient gradients (P < 0.01). While Avicannia africana in the A stratum was influenced largely by the salinity and soil texture gradients. Nypa fruticans in the B stratum was influenced by salinity and nutrients. 相似文献
67.
孙殿芝 《内蒙古林业调查设计》2007,30(2):15-16
文章在分析牙克石市自然条件及水土流失特点的基础上,提出牙克石市水土保持生态修复的可行性及生态修复的措施,以及近年来牙克石市生态修复所取得的可喜成果。 相似文献
68.
Hongjun Yang Jiangbao Xia Wenjun Xie Shoucai Wei Qian Cui Pengshuai Shao Jingkuan Sun Kaikai Dong Xingchao Qi 《Land Degradation u0026amp; Development》2023,34(7):2061-2072
The effects of different straw returning and nitrogen addition levels on soil quality are important for proper coastal saline soil remediation. However, relatively little is understood concerning the remediation effects, especially, on long-term effects and mineral composition and microstructures of coastal saline soil. Two maize/wheat straw returning levels [1.0 × 104 kg ha−1 (2S) and 5.0 × 103 kg ha−1 (S)] and three inorganic nitrogen addition levels [300 kg ha−1 (N2), 150 kg ha−1 (N) and 75 kg ha−1 (N1/2)]—were studied, with 150 kg ha−1 inorganic nitrogen and without straw addition treatment as the control (CK), to elucidate the response of soil physical and chemical properties to the two factors. After four consecutive wheat-maize cycles, different straw and N fertilizer treatments obviously decreased the salinity contents, increased the total nutrient contents, and optimized the soil structure of the saline soil. The saline soil reclamation effects showed significant distinctions among the different straw and N fertilizer treatments. The 2SN2 treatment displayed the greatest effects in regard to reducing salinity, increasing the total soil nutrient contents and optimizing the soil structure, which resulted in the best remediation effect. Straw returning plays a major role in decreasing soil salinity and enhancing saline soil aggregate formation. N fertilizer addition supplies rich nutrients for straw decomposition, and promotes soil microbial growth and reproduction, which brought about C sequestration in coastal saline soil. During the coastal saline soil remediation process in the Yellow River Delta, it is suggested to prioritize straw returning and moderate N fertilizer addition, and live together with moderate P fertilizer application. 相似文献
69.
P. J. O'Connor M. B. Lynch E. Cahalan M. O'Donovan D. Hennessy 《Grass and Forage Science》2013,68(4):564-576
A cut plot experiment was undertaken at two sites in Ireland, one a free‐draining acid brown earth at Moorepark (MPK) and the other a fine loam soil with imperfect drainage at Johnstown Castle (JC). The effect of applying the nitrification inhibitor dicyandiamide (DCD) at 10 kg ha?1 in July, August and September or not applying DCD to plots receiving synthetic urine or zero urine on spring and annual herbage production was examined. In the experiment, each site received 350 kg nitrogen (N) fertilizer ha?1 year?1. The application of DCD in August at a rate of 10 kg ha?1 significantly increased spring and annual herbage production by 14 and 15%, respectively, at MPK, when applied following urine application in year 1. There was no effect of DCD applied in year 1 on herbage production at JC. The application of DCD in August resulted in lower soil total oxidized N (TON) content up to sampling day 56 post‐urine application, at MPK in year 1, retaining higher N content in the soil. There was no effect of DCD on any of the parameters measured in year 2 at MPK or at JC. Urine application did not increase spring herbage production at either site. Urine application significantly increased annual herbage production at MPK only in year 1. Urine application increased annual herbage N uptake, herbage crude protein (CP) content and soil mineral N at both sites in both years. 相似文献
70.
沧州滨海盐碱地造林绿化技术 总被引：5，自引：0，他引：5
根据沧州滨海地区的自然状况,提出了滨海盐碱地区造林绿化的基本观点,及采取的造林绿化技术措施,并推介了一批该地区的适生树种。 相似文献