水稻秸秆肥料^15N标记的不均匀性研究

在盆栽条件下研究了水稻秸肥料＾１５Ｎ标记的不均匀性及其对示踪试验结果的影响问题。结果表明，以基肥、分蘖肥、穗肥三种方法进行＾１５Ｎ标记的秸秆，其茎叶及其化学组成间＾１５Ｎ原子百分超都存在不同程度的差异。秸秆肥料示踪试验的结果，受供试秸秆肥＾１５Ｎ标记不均匀性影响，很可能出现偏高或偏低的情况。     

低丰度富集^15N示踪研究中的几个问题

本文介绍了低丰度富集＾１５Ｎ示踪研究中质量分析相对误差的控制办法，一般示踪试验中标记肥料合适丰度值的确定方法，以及该技术的应用前景。     

应用^15N示踪技术土壤水分对氮素有效性的影响

在有防雨设施的试验田里,设置不同的土壤水分处理,应用＾１５Ｎ示踪技术研究土壤水分对氮素有效性的影响。试验结果表明：冬小麦对肥料氮素的利用率随土壤水分提高而提高;土壤供应的有效性氮素（Ａ值）在土壤水分由田间持水量的５０％提高到６０％时出现“跃迁”,土壤水分超过田间持水量的６０％以后,Ａ值差异不显著,表明土壤氮素有效性对土壤水分存在一个阈值反映。节水、节肥高效的土壤水分下限应控制在土壤田间持水量的６０     

稻田脲酶抑制剂对^15N—尿素去向的影响

尿素施入稻田后迅速水解成ＮＨ＾＋４，两天后水层ＨＮ＾＋４－Ｎ含量即达峰值，混施脲酶抵制剂后，峰值可推迟１天，峰高降低，＾１５Ｎ示踪试验表明：ＰＰＤ和ＮＨＰＴ两种抑制剂能明显促进水稻对氮素的吸收，亦提高水稻对尿素氮的利用率，减少损失率，并在一定程度上具有增产效果，尤其是在高氮水平下，效果更加明显，而ＨＱ则较差。稻草的施用对水稻生长有一定的影响，降低了水稻对肥料氮素的吸收，但能能提高肥料氮素在土壤中的     

应用15N示踪研究麦秸还田中氮的去向

应用¹⁵N示踪技术研究了麦秸铺施和混施方式下,秸秆中氮在土壤中的去向。试验结果表明:1.麦秸铺盖土表还田的,夏谷地上部分和籽粒部分对秸秆氮的利用率分别为28.3%和15.2%,而麦秸与土壤混合施用还田的,其对秸秆氮的利用率则分别为20.6%和12.0%。前者明显优于后者。2.夏谷生长87天后,麦秸铺施还田的,秸秆氮有28.3%进入夏谷株体中;16.5%进入土壤腐殖质;0.5%和3.1%分别进入渗漏水和以气态等形式逸失;残留于土壤中的秸秆氮(包括夏谷根系)约有51.6%。而麦秸混施还田的,秸秆氮进入夏谷株体、土壤腐殖质、渗漏水和以气态逸失的量分别占施入秸秆氮总量的20.5%,14.8%,0.2%和11.5%,残留于土壤中的约占总量的53.0%。     

Crop uptake of 15N labelled fertilizer in spring wheat affected by application time

Time of nitrogen fertilizer application on crop recovery was studied in a field experiment at Foulumgaard, Denmark, in 2001. A solution of ¹⁵N-ammonium-¹⁵N-nitrate was applied in bands parallel to a single row of spring wheat grown in frames of 30 cm×40 cm. The labelled fertilizer was applied on 16 dates with intervals of 4–5 days from tillering to the start of grain-filling. Crop ¹⁵N recovery increased by 0.47%-point day^?1 when the time of fertilizer application was postponed from tillering until the second node stage (GS32). On the other hand, a decrease in crop ¹⁵N recovery of –0.19%-point day^?1 was recorded from GS47 to maturity (GS85–87). The effect of the 16 application times on ¹⁵N recovery was described by two straight lines having intersection at the time of full expanded flag leaf and ear emergence halfway (GS55). It was concluded that leaf area expansion is important for crop N demand and ¹⁵N recovery.     

Burning effects on the distribution of organic N compounds in a 15N labelled forest soil

Nitrogen distribution was studied, by successive 1 M (H1) and 3 M HCl (H2) hydrolyses, on a natural soil before (NS) and after ¹⁵N labelling (LS) in an incubation chamber and burning (BLS) in a furnace simulating an intense fire (385 °C, 10 min). The labelling increased the organic-N of H1 (H1-N) by 4.7%, due to the increase in hydrolyzable unidentified-N (HU-N, 66.3%) and amino acids (AA-N, 11.2%), which counterbalanced the reduction of amides (AM-N, 33.2%) and amino sugars (AS-N, 68.0%). After labelling, H2-N decreased by 7.5%, mainly due to the reduction of AA-N (12.2%) and AS-N (14.9%); conversely, ammonium-N (A-N) and non-hydrolyzable-N (NH-N) did not vary and total organic-N increased slightly (2.4%). In LS, the ¹⁵N labelling decreases as follows: H1-N (with AM-N>AS-N>AA-N≈HU-N)>H2-N (with HU-N>AA-N≈A-N>AS-N)>NH-N. The added ¹⁵N was mainly incorporated in organic forms (92.2%), following the distribution of the endogenous organic-N; nevertheless, the higher proportion of recently incorporated ¹⁵N in hydrolyzable fractions, and lower in NH-N, showed that it is more labile than endogenous N. The added ¹⁵N undergoes similar, but stronger, transformations and losses due to burning than the native N: (1) 18.1% of endogenous-N and 22.4% of exogenous-N were lost; (2) H1-N, H1-¹⁵N, H2-N, H2-¹⁵N, AA-N, AA-¹⁵N, HU-N and HU-¹⁵N decreased by 69.7%, 74.1%, 76.6%, 82.9%, 96.5%, 96.8%, 92.1% and 98.3%, respectively; (3) NH-N, NH-¹⁵N, A-N and A-¹⁵N increased by 81.0%, 314%, 81.3% and 78.2%, respectively; (4) AM-N increased (51.2%) whereas AM-¹⁵N decreased (1.7%). Therefore, soil burning reduces the soil organic N reserves, through N volatilization (especially of labile N), and decreases N bio-availability, through an important net transfer of N from the labile to the recalcitrant pool; jointly, both processes will increase the negative effects of wildfires on the N cycle. In spite of the previous ¹⁵N labelling process, LS could be considered as a representative forest soil, which undergoes similar changes during burning than unlabelled soils, leading to a representative burnt labelled soil. Neither in LS nor in BLS the distribution of the added ¹⁵N was uniform among the N fractions; nevertheless, as the reference levels of ¹⁵N enrichment in the organic N fractions are accurately known, both LS (as control treatment) and BLS will be useful for further studies on the efficiency of several techniques on the post-fire restoration of the soil N distribution.     

对生物有机肥生产工艺选择的几个问题的思考

本文介绍了生物有机肥的特点及发展前景,描述了生产生物有机肥的几种生产工艺,并对各生产工艺进行比较。     

Effect of increasing rates of 15N‐labelled fertilizer on recovery of fertilizer N in plant and soil N pools in a pot experiment with winter wheat

The effect of increasing rates of ¹⁵N‐labelled Ca(NO₃)₂ (N₀ = no N application, N₃₀₀ = 300 mg N/pot; N₆₀₀ = 600 mg N/pot; N₉₀₀ = 900 mg N/pot) on recovery of fertilizer N in winter wheat plants and soil (total soil N, soil microbial biomass N [N_mic], extractable organic N [N_org]) and on N mineralization (NM_soil) was investigated at milk‐ripe growth stage in a pot experiment. The N rates were equally split at tillering, stem elongation and ear emergence. Fertilizer N recovered in crops increased with increasing N rates (N₃₀₀: 223.5 mg N/pot [74.5% of applied fertilizer N], N₆₀₀: 445.6 mg N/pot [74.3%], N₉₀₀: 722.1 mg N/pot [80.2%]). NM_soil slightly increased from N₀ (43.8 mg N/pot) to N₉₀₀ (75.6 mg N/pot) indicating that N application enhanced availability of soil‐derived N for the plants. However, in fertilized treatments NM_soil is balanced by immobilization and losses (non‐recovered fertilizer N). Therefore the effective soil N mineralization is indicated by apparent net N mineralization (ANNM = NM_soil — fertilizer N immobilization — lost fertilizer N). Fertilizer N immobilization in soil increased from N₃₀₀ (38.7 mg N/pot) to N₆₀₀ (60.7 mg N/pot) and N₉₀₀ (65.5 mg N/pot). Lost fertilizer N increased from N₃₀₀ (14.8 mg N/pot) to N₆₀₀ (56.7 mg N/pot) and N₉₀₀ (62.1 mg N/pot). As a consequence negative ANNM values were calculated at N₆₀₀ and N₉₀₀. Due to the small differences between N₆₀₀ and N₉₀₀ fertilizer N immobilization and lost fertilizer N did not increase linearly with increasing N rates, i.e. both processes were limited by factors other than N rate. Only 5.6—7.4% of the immobilized fertilizer N was recovered in N_org and 5.4—9.3% in N_mic soil pools. It is assumed that most of the immobilized fertilizer N was in non‐extractable organic N forms. N_mic and N_org were weak indicators for the extent of fertilizer N immobilization.     

Effects of two soil reclamation techniques on the distribution of the organic N compounds in a 15N labelled burnt soil

The evolution of the soil organic-N forms and their bio-availability was studied in a ¹⁵N labelled and burnt soil (BLS) after two successive reclamation steps under greenhouse conditions: a 3-month growing period of Lolium, without (BLS-L) or with poultry manure addition (4 and 8 Mg ha^− 1: BLS + PM4-L and BLS + PM8-L), followed by a 12-month growing phase of pine seedlings (BLS-P, BLS + PM4-P and BLS + PM8-P). The results were compared with those obtained for the homologous labelled unburnt soil (LS, LS-L and LS-P) to evaluate the efficacy of these reclamation techniques in the mitigation of the drastic post-fire changes exhibited by the major biologically available N pool in terrestrial ecosystems: the soil organic N. The significant and steady decrease of the ¹⁵N enrichment observed in the unburnt soil during the successive plant growth cycles (LS > LS-L > LS-P) contrasts with the lack of significant changes, in both the content of total organic ¹⁵N and the atom % ¹⁵N in excess, among the treatments with the burnt soil (BLS ≥ BLS-L ≥ BLS-P). These results showed that: a) in LS, N mineralization proceeds faster for the recently incorporated N (¹⁵N enriched) than for the native N, supplying the growing vegetation with inorganic N more ¹⁵N enriched than the bulk soil N; and b) in BLS, soil combustion has reduced the usually higher biological availability of the recently added N to levels similar to those of the endogenous N.The re-vegetation with Lolium and Pinus and the addition of poultry manure mitigated the high differences observed in the size of the amino acid and the organic derived NH₄⁺–N pools due to the combustion process, which are usual between burnt and unburnt soils. Conversely, these burnt soil reclamation techniques (re-vegetation and poultry manure addition), even jointly used, were unable to reduce the huge differences observed between the burnt and the unburnt soils for the other N fractions considered (amides, amino sugars, hydrolysable unidentified-N, hydrolysable organic N and un-hydrolysable N) that accounted for more than 80% of the soil organic N. Consequently, it seems that without the introduction of N₂-fixing microorganisms or plants in the burnt soils the recovery of the natural soil organic N composition will take place slowly.     

氮磷与有机肥配施对小麦光合作用及产量和品质的影响

研究了氮磷与有机肥配施条件下小麦(陕512品种)不同叶位与茎蘖功能叶光合速率、产量及其构成因素和品质指标的变化。结果表明,不同施肥处理对不同叶位和茎蘖功能叶光合速率有显著的调节作用,处理间、茎蘖间、叶位间功能叶光合速率差异极显著,同时处理与叶位之间的互作对灌浆期功能叶光合速率有极显著的作用。与常规施肥对照相比,氮磷与有机肥配合使用,可显著提高生育后期不同叶位和茎蘖功能叶光合速率,旗叶和倒二叶分别提高30.9%和21.9%;主茎、蘖一和蘖二提高21.8%、36.6%和28.3%;次生根增加12.5%2～8.3%,分蘖增加11.1%2～9.7%,孕穗期单株干物质积累量增加15.5%。同时,子粒品质也显著提高,稳定时间增加80.3%,蛋白质增加4.1%;降落值降低6.1%,吸水率降低7.2%;成穗数增加6.3%,穗粒数降低4.0%,产量增加5.2%。     

棚式袋装发酵法生产有机肥技术研究初报

对传统条垛发酵、棚式条垛发酵、一般袋式发酵、棚式袋装发酵法进行了堆料外观、堆料温度、堆料全N、全C、C/N变化等对比试验和成本效益分析.结果表明,棚式袋装发酵法能较好地解决堆肥发酵过程中通气、温度、水分的调控问题,具有堆制时间较短、保肥性较好、除臭效果好、腐熟化、无害化程度高、堆肥质量优等优点,且该法能充分利用太阳能和生物好氧发酵自身产生的热量自然干燥,可免去翻抛、烘干设备,投资成本低、运行和维护费用省、技术工艺方便易行,适合于中小型商品有机肥生产企业和养殖场的粪便就地无害化处理.     

我国有机肥资源及产业发展现状

科学减施化肥用量，合理配施有机肥对土壤肥力提升、农产品增质和减轻面源污染有着重要的意义。我国农业有机废弃物资源丰富，有机养分总量达到约 7 519.5万 t，其中 N、P 2O5、K2O养分总量分别为 3 096.3万、1 174.1万、3 249.1万 t，但是目前资源利用率不足 40%，不仅造成优良有机养分资源的浪费，同时带来环境污染风险的问题。如何高效利用有机肥资源是我国目前亟需解决的问题。本文总结有机肥相关文献和他人研究结果，综述了我国有机肥资源数量、利用现状，针对施用的问题，对产业发展提出了一些建议。     

化肥减量配施有机肥对葡萄产量、品质及土壤质量的影响

以5年生"巨峰"葡萄为试验材料,按照不同化肥减量比例配施有机肥,开展连续2年的田间试验,研究不同化肥减量配施有机肥对"巨峰"葡萄产量、品质及土壤质量的影响,以期获得最佳的化肥减量配施有机肥比例.结果表明:化肥减量配施有机肥各处理与单施化肥(CK)相比,不仅使葡萄产量和品质得到提高,还能有效减少土壤大量元素的累积,提高土...     

化肥减量配施有机肥对土壤有机碳及其组分的影响

为了探究化肥减量配施两种不同黄腐酸钾有机肥对土壤有机碳及其组分的影响,采取盆栽模拟大田种植,以不施肥和纯施化肥为对照,以100%化肥配施100%有机肥、75%化肥配施25%有机肥、50%化肥配施50%有机肥、25%化肥配施75%有机肥和100%有机肥为处理,探讨土壤有机碳（SOC）、可溶性有机碳（DOC）、微生物量碳（MBC）、易氧化有机碳（LOM）和惰性有机碳（ROC）在不同生育期内的含量特征。结果表明：化肥减量配施有机肥各处理有机碳及其组分含量各生育期均表现为：花针期显著高于结荚期和成熟期,其中可溶性有机碳和微生物量碳结荚期含量显著高于成熟期（P＜0.05）;各处理有机碳及其组分含量均表现为：25%化肥配施75%生化黄腐酸钾处理显著高于不施肥、单施化肥和单施有机肥处理,50%化肥配施50%矿源黄腐酸钾处理显著高于不施肥、单施化肥和单施有机肥处理;其中花针期25%化肥配施75%生化黄腐酸钾处理SOC、DOC、MBC、LOM和ROC含量分别为133.0 g·kg-1、284.4 mg·kg-1、269.7 mg·kg-1、30.76 g·kg-1和111.2 g·kg-1,50%化肥配施50%矿源黄腐酸钾处理SOC、DOC、MBC、LOM和ROC含量分别为130.9 g·kg-1、250.5 mg·kg-1、251.7 mg·kg-1、29.86 g·kg-1和110.8 g·kg-1。综上,化肥减量配施生化黄腐酸钾对土壤有机碳及其组分含量的影响整体优于配施矿源黄腐酸钾（P＞0.05）,各生育期有机碳及其组分含量均表现为：化肥减量配施黄腐酸钾花针期显著高于结荚期和成熟期（P＜0.05）,其中25%化肥配施75%生化有机肥处理对提升土壤中有机碳及其组分含量效果最佳,其SOC、DOC、MBC、LOM和ROC含量各生育期分别增加0.15%-13.50%、3.45%-122.11%、15.37%-133.54%、2.56%-60.44%和0.36%-18.80%。