氮、硫供应水平对芜菁硫代葡萄糖苷含量的影响

硫代葡萄糖苷（GS）含量的多少是芜菁品质好坏的重要指标。本文采用沙培试验、 高效液相色谱法（HPLC）研究不同氮（80 kg/hm2、 160 kg/hm2和240 kg/hm2）和硫（10 kg/hm2和60 kg/hm2）供应水平对白玉芜菁叶和根中硫代葡萄糖苷组成和含量的影响。结果表明, 白玉芜菁叶片中有7种硫代葡萄糖苷,根中有9种硫代葡萄糖苷。叶片中总硫代葡萄糖苷含量是根部总硫代葡萄糖苷含量的1.16倍。增加硫供应水平,显著增加了根和叶中各种硫苷含量;随着氮供应水平的增加,吲哚族硫苷含量占总硫苷含量的比例显著增加。白玉芜菁中硫代葡萄糖苷的含量决定于氮和硫的平衡供应,在氮N 160 kg/hm2、 硫S 60 kg/hm2供应水平下硫代葡萄糖苷含量最高。     

过量施氮对旱地土壤碳、氮及供氮能力的影响

【目的】过量施氮会影响土壤有机碳、氮的组成与数量,进而改变土壤供氮能力,但关于西北旱地长期过量施用氮肥后土壤有机碳、氮及土壤供氮能力变化的研究尚缺乏。本文在长期定位试验的基础上,通过分析不同氮肥水平特别是过量施氮条件下土壤硝态氮,有机碳、氮和微生物量碳、氮的变化,探讨长期过量施氮对土壤有机碳、氮及供氮能力的影响。【方法】长期定位试验位于陕西杨凌西北农林科技大学农作一站。在施磷(P2O5)100kg/hm2的基础上,设5个氮水平,施氮量分别为N 0、80、160、240、320 kg/hm2。重复4次,小区面积40 m2,完全随机区组排列。种植冬小麦品种为小堰22。本文选取其中3处理,以不施氮为对照(N0)、施氮量N 160 kg/hm2为正常施氮(N160),施氮量N 320 kg/hm2为过量施氮(N320),分别于2012年6月小麦收获后和10月下季小麦播前采集土壤样品,进行测定分析。【结果】过量施氮导致下季小麦播前0—300 cm各土层硝态氮含量显著增加,平均由对照的2.8 mg/kg增加到15.5 mg/kg;同时,0—60 cm和0—300 cm土层的硝态氮累积量分别由对照的47.2和108.9 kg/hm2增加到76.5和727.7 kg/hm2。过量施氮也增加了夏闲期间0—300 cm土层土壤有机氮矿化量,由对照的72.4 kg/hm2增加到130.7 kg/hm2。但过量施氮未显著增加土壤的有机碳含量,却显著增加了土壤有机氮含量,过量施氮0—20、20—40 cm土层土壤有机碳分别为9.24和5.39 g/kg,有机氮分别为1.05和0.71 g/kg,较对照增加52.2%和54.3%。同样,过量施氮未显著影响0—20、20—40 cm土层土壤微生物量碳含量,其平均含量分别为253和205 mg/kg,却显著提高了0—20、20—40 cm土层土壤微生物量氮含量,由对照的24.1和7.5 mg/kg提高到43.6和16.1 mg/kg。【结论】过量施氮可以显著增加旱地土壤剖面中的硝态氮累积量、夏闲期氮素矿化量、小麦播前土壤氮素供应量和土壤微生物量氮含量,但对土壤有机碳和微生物量碳没有显著性影响,同时过量施氮增加了土壤硝态氮淋溶风险,故在有机质含量低的黄土高原南部旱地冬小麦种植中不宜施用高量氮肥,以减少土壤氮素残留和农业投入,达到保护环境和培肥土壤的目的。     

Sulfur and nitrogen supply influence growth,product appearance,and glucosinolate concentration of broccoli

The effects of insufficient and optimal sulfur (S) and nitrogen (N) supply on plant growth and glucosinolate formation were studied under controlled experimental conditions in broccoli “Monaco”. Here, we report on the interaction between S and N supply, plant growth, and quality parameters and discuss the relevance of this interaction in relation to crop‐management strategies. Broccoli plants supplied with insufficient amounts of S or N showed typical deficiency symptoms and yield decreases. In contrast, total glucosinolate concentrations were high at insufficient N supply, independent of the S level, and low at insufficient S supply in combination with an optimal N supply. This was mainly due to the presence of the alkyl glucosinolates glucoraphanin and glucoiberin. Furthermore, with S concentrations above 6 g (kg DM)^–1 and an N : S ratio lower than 10:1, the glucosinolate concentrations were on average around 0.33 g (kg fresh matter)^–1 and differed significantly from those plants characterized by an S concentration below 6 g (kg DM)^–1 and an N : S ratio above 10:1. In addition, N : S ratios between 7:1 and 10:1 promoted plant yield and enhanced overall appearance. Therefore, to produce broccoli (and potentially other Brassicaceae) with higher crop yields and enhanced product quality in the field, it is vital to establish the optimal S and N nutritional status of the plant and to integrate this information into crop‐management strategy programs.     

长期不同氮、 磷用量对冬小麦籽粒锌含量的影响

【目的】小麦是我国西北地区主要的粮食作物,主要种植在低锌的石灰性土壤上,其籽粒锌含量普遍较低,难以满足人们的锌营养需求,因此提高冬小麦籽粒中的锌含量对保证人体健康具有非常重要的意义。氮素、 磷素供应不足或过量会影响冬小麦对锌的吸收与利用,本文基于黄土高原南部9年的长期定位试验,研究了长期不同氮、 磷肥用量对旱地冬小麦籽粒锌含量的影响及籽粒锌含量与氮、 磷吸收与分配的关系,以期为有效调控冬小麦籽粒锌营养品质和优化旱地冬小麦氮、 磷肥管理提供理论依据和切实可行的措施。【方法】田间定位试验开始于2004年10月,位于陕西杨凌西北农林科技大学农作一站。采用单因素完全随机区组设计,重复4次。供试小麦品种为小偃22,整个生育期不灌水。试验一为小麦施氮量试验,在施磷量为P2O5100 kg/hm2的基础上,设置0、 80、 160、 240、 320 kg/hm2 5个氮肥(N)水平;试验二为小麦施磷量试验,在施氮量为N 160 kg/hm2的基础上,设置P2O5 0、 50、 100、 150、 200 kg/hm2 5个磷肥水平。分别于2011～2013年连续两年进行田间取样,测定小麦籽粒产量及其构成因素,籽粒、 茎叶和颖壳中的氮、 磷、 锌含量,计算小麦地上部的氮、 磷、 锌吸收量。【结果】小麦施氮量试验表明,氮肥用量不超过N 320 kg/hm2时,小麦籽粒锌含量和地上部锌吸收量与施氮量呈极显著的正相关关系,施氮量每增加N 100 kg/hm2,籽粒锌含量平均提高4.0 mg/kg,地上部锌吸收量平均提高36.4 g/hm2;籽粒中的锌含量与氮含量之间、 地上部的锌吸收量与氮吸收量之间也均呈极显著的正相关关系,籽粒氮含量每增加1 g/kg,籽粒锌含量平均提高2.0 mg/kg,地上部氮吸收量每增加100 kg/hm2,其锌吸收量平均提高142.9 g/hm2。小麦施磷量的试验结果表明,施磷量不超过200 kg/hm2时,籽粒锌含量与施磷量呈极显著的负相关关系,施磷量每增加P2O5 100 kg/hm2,籽粒锌含量平均下降9.2 mg/kg;籽粒锌含量与磷含量也呈极显著的负相关关系,籽粒磷含量每增加1 g/kg,籽粒锌含量平均降低24.0 mg/kg;地上部锌吸收量与施磷量、 地上部磷吸收量之间均没有显著相关关系。【结论】综合考虑冬小麦籽粒产量和籽粒锌含量,建议这一地区冬小麦的施氮量和施磷量分别控制在N 160～240 kg/hm2和P2O5 50～100 kg/hm2。     

Effects of repeated straw incorporation on crop fertilizer nitrogen requirements, soil mineral nitrogen and nitrate leaching losses

Abstract. The effects of straw disposal by burning and incorporation on soil and crop nitrogen (N) supply, were investigated on two light textured soils in central (ADAS Gleadthorpe) and eastern England (Morley Research Centre) over the period 1984 to 1995. Nitrogen balance calculations showed that after 11 years of contrasting straw incorporation versus burn treatments, the cumulative N returns in straw were c . 570kg/ha at Gleadthorpe and c . 330 kg/ha at Morley However, these N returns via straw incorporation were not reflected in increased total soil N levels in autumn 1994. There were no differences ( P > 0.05) between straw disposal treatments in autumn soil mineral N supply, readily mineralizable N or organic carbon. Similarly, there were no consistent differences between the treatments in terms of crop yield, crop N uptake or optimum fertilizer N rates. Fertilizer N applications of 200 kg N/ha/y increased topsoil organic carbon from 1.18 to 1.28% and total N content from 0.091 to 0.102% on the loamy sand textured soil at ADAS Gleadthorpe, but not at Morley. Previous fertilizer N applications increased the quantity of nitrate-N leached in drainage water by c . 20 kg/ha at Gleadthorpe and c . 60 kg/ha at Morley overwinter 1994/95, and by 10–20 kg/ha at both sites overwinter 1995/96. There was some indication overwinter 1994/95 that straw incorporation reduced nitrate-N leaching by 10–25 kg/ha, but there were no differences between treatments overwinter 1995/96.     

Storage life of field-grown garlic bulbs (Allium sativum L.) as influenced by nitrogen and sulfur fertilization

The most important active compound in garlic is alliin. Sulfur (S) fertilization was shown to significantly increase the alliin concentration in garlic cloves, while high nitrogen (N) levels had an adverse effect. The effect of graded N and S application on the storage life of garlic has been paid little attention so far. A bifactorial field trial with 4 levels of N and S was conducted in a randomized block design. At harvest, 40 bulbs per treatment were stored under terms comparable to the storage conditions in average households (20 °C, dry, and dim) for 83 days. Every 3 weeks, samples were analyzed for their alliin and water content. The alliin concentration in peeled garlic cloves increased during storage from on average 9.2 mg g(-1) dry weight at harvest to 21.4 mg g(-1) dry weight after 83 days of storage. S fertilization increased the alliin concentration by a factor of 2.3 from 11.4 mg g(-1) in the control treatment to 26.6 mg g(-1) dry weight at the highest S level of 45 kg ha(-1) after 83 days of storage. N fertilization decreased by a trend of the alliin content. Fertilizer rates had only a minor influence on water losses from bulbs at short-term storage. After 83 days of storage, water losses were by trend lower at higher S levels, and this relationship proved to be significant when no N was applied. Best quality in terms of high alliin contents was obtained during the entire storage time at an S level of at minimum 30 kg ha(-1) S if no N was applied. The results show that the physiological S demand of 15 kg ha(-1) S for optimum yield is lower than the S requirement of 30 kg ha(-1) S for a longer storage life.     

硫肥对双低油菜产量与品质的影响

在澳大利亚新南威尔士州缺硫土壤上进行了硫、氮不同水平组合对双低油菜(Canola)的影响试验。结果表明,试验条件下施用硫肥可显著提高油菜产量及含油量。低硫(S10)或无硫(So)条件下,一定量的氮肥(N80)可提高子粒内的含硫量,但高硫条件下,高量氮肥则降低含硫量。植株体内的含硫量随生育进程趋于降低。施硫处理在抽苔期出现一吸硫高峰,而对照呈指数下降;但在开花期与角果充实期则保持相对稳定。氮肥对生长前期(莲座期与抽苔期)植株(茎、叶)含硫量的影响不显著,而中、后期(开花、角果充实期),则随施氮量的增加而显著降低。高量氮肥(N160)会降低子粒内的硫代葡萄糖甙含量;施硫,特别是在高施硫量条件下,其含量则明显增加,但仍远低于子粒硫代葡萄糖甙40mol/g的标准,因而不会影响脱油饼粕的饲喂质量。     

Influence of Cocoa Pod Husk-Based Compost on Nutrient Uptake of Okra (Abelmoschus esculentus (L.) MOENCH) and soil properties on an Alfisol

This experiment evaluated the potentials of cocoa pod husk (CPH)-based compost on okra and soil chemical properties. Three CPH-based compost: CPH+ Neem leaf (CPH+ NL), CPH+ Poultry manure (CPH+ PM) and CPH+ PM+ NL were prepared. The treatments; 25, 50, 75, 100 kg N/ha of each compost and NPK mineral fertilizer at 40, 50, 60 kg N/ha and control, were applied to 5 kg soil each and arranged in a completely randomized design in three replicates. Two varieties of okra (NH47-4 and LD88) were grown for six weeks and residual effect evaluated. The Nitrogen, Phosphorus, and Potassium uptake of okra were determined. Pre- and post-cropping soil analyses were done. Data were analyzed using ANOVA and means separated by Duncan Multiple Range Test at α_0.05. The results showed that the nutrient uptake of okra consistently increased with CPH-based compost compared to control in both main and residual cropping. Nitrogen uptake ranged from 53.6 (60 kg N/ha NPK) to 106.7 (50 kg N/ha CPH+ PM) and 16.10 (50 kg N/ha NPK) to 55.06 (25 kg N/ha CPH+ PM+ NL); Phosphorus uptake ranged from 6.9 (25 kg N/ha CPH+ NL) to 24.1 (60 kg N/ha NPK) and 3.70 (25 kg N/ha CPH+ NL) to 9.98 (50 kg N/ha CPH+ PM+ NL), while potassium uptake ranged from 166.4 (25 kg N/ha CPH+ NL) to 244.48 (25 kg N/ha CPH+ PM+ NL) and 64.06 (40 kg N/ha NPK) to 122.29 (75 kg N/ha CPH+ NL) mg/plant in main and residual cropping, respectively. Organic carbon, pH, nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg) and sodium (Na) were also significantly increased by the CPH-based compost. It could, therefore, be concluded that CPH-based compost could be a good fertilizer for okra production.     

Influence of nitrogen levels and plant spacing on growth,productivity and quality of two inbred varieties and a hybrid of aromatic rice

A field investigation was conducted at the Indian Agricultural Research Institute's Research Farm during the kharif (wet) seasons of 2002 and 2003 in a split plot design with three replications, consisting of 27 treatments, namely, main plots: three varieties (PRH-10, Pusa Sugandh-3 and Pusa Basmati-1) and three plant spacings (20 × 10, 20 × 15 and 20 × 20 cm²) and sub-plots: three levels of nitrogen (0, 80 and 160 kg N ha^?1). The research results indicated that aromatic rice hybrid PRH-10 produced 33 and 6%, respectively, more grain yield than that of Pusa Sugandh-3 and Pusa Basmati-1. The appreciable higher grain yield of PRH-10 over Pusa Sugandh-3 and Pusa Basmati-1 was due to considerable improvement in most of the yield attributing characters. Application of 160 kg N ha^?1 recorded 23.7 and 26.1% more grain yield over no nitrogen application whereas it was 6.4 and 6.1% more over 80 kg N ha^?1, respectively, during first and second year of the experimentation. Wider plant spacing of 20 × 20 cm² and application of 160 kg N/ha recorded significantly higher hulling, milling and head rice recovery compared to closer spacing and zero nitrogen application.     

Effect of N,P and K fertilizers on their availability in soil in relation to the Stevia plant (Stevia rebaudiana Bert.)

Abstract

A greenhouse experiment was conducted at the Indian Institute of Horticultural Research (IIHR), Bangalore, to study the effect of combined applications of nitrogen (N), phosphorous (P) and potassium (K) fertilizers on their availability in soils in relation to their contents in the Stevia plant. The results show that the amount of available N, P and K in soil has been found to be increased initially up to 45 days and thereafter, the amount of the same content decreased with the progress of plant growth up to 60 days irrespective of treatments. However, the magnitudes of such increases in N, P and K contents both in soils and plants have also been enhanced with the simultaneous application of N, P and K (40:20:30) kg/ha over that of their corresponding individual applications.     

氮、硫配施对冬小麦氮素利用效率及产量的影响

【目的】氮(N)、硫(S)是生物所必需的营养物质,对小麦籽粒产量和品质起着重要作用。硫素供应不足,特别是在当前大量氮素供应情况下引起的作物生理性缺硫将导致作物产量和含硫氨基酸蛋白质含量下降。本文旨在探索氮、硫配施对冬小麦氮素利用效率和籽粒产量的促进效果并提出合理的区域氮、硫施肥技术。【方法】20122013年,在河南温县以国审冬小麦品种豫麦49-198为供试材料,进行大田试验。设置不同施氮量0、120、180、240和360 kg/hm2(分别以N0、N120、N180、N240和N360表示)和施硫0和60 kg/hm2(S0和S60)试验,调查氮、硫对冬小麦干物质积累、氮素积累分配、籽粒产量和氮素利用效率的影响。【结果】对冬小麦生育后期干物质积累分析表明,干物质积累随施氮量增多而提高,相同施氮量条件下施硫较不施硫小麦干物质积累量显著提高,其中成熟期干物质积累量N180S60、N240S60和N360S60分别较N180S0、N240S0和N360S0提高2225、3607和3120 kg/hm2,而且氮素低的处理添加硫后干物质积累量高于氮素高不加硫处理,如N180S60N240S0、N240S60N360S0,处理间差异均达显著水平。随施氮量增多,冬小麦植株氮素积累总量增加,在N 240和360 kg/hm2水平,硫素供应显著增加小麦植株氮素积累。不同施氮量条件下施硫较不施硫均显著提高了小麦籽粒产量,分别提高了10.5%、18.3%、5.2%、5.6%和4.9%。随施氮量增多,氮肥偏生产力下降,氮回收效率、生理效率和农学效率则均以N 180达最高值。不同施氮水平下,施硫均显著提高了冬小麦氮素回收效率,但对氮生理效率影响不显著,其中在施N量为120、180和240kg/hm2时,施硫较不施硫氮肥偏生产力和农学效率均显著提高。【结论】在当前小麦生产中,采用控氮或减氮增硫技术措施,可实现小麦氮利用效率和籽粒产量的同步提高。在本试验地区小麦生产中,达到冬小麦稳产高效或增产高效的适宜施氮量为180 240 kg/hm2配合60 kg/hm2硫肥施用。     

Nitrogen utilization efficiency variability in genotypes of Indian mustard (Brassica juncea) under contrasting N supply

Abstract

Identifying genotypes of high nitrogen utilization efficiency (NUtE) under contrasting N supply is a way of improving N economy of Indian mustard (Brassica juncea Czern &; Coss) under different soil fertility. A field experiment was conducted with 22 Indian mustard genotypes grown under normal and limited N supply conditions to investigate the genotypic variations of NUtE. The genotypes ranking to NUtE was different under normal and limited N supply, however, seven genotypes (RH 1222-28, RH 1301, RH 1117, RH 601, RH 1053, NRCDR 2, RH 1441) were identified as N-responder under normal N supply, and N-efficient under limited N supply. The lowest seed yield reduction (<20%) under limited N supply was recorded in RH 601 (15%), RH 1301 (17%), RH 1215 (17%), and DRMRIJ 31 (18%) compared to normal N supply. Among these genotypes, DRMRIJ 31 and RH 1215 were the highest seed yielder (>3.0 t/ha) under normal N supply and RH 601 (>2 t/ha) under limited N supply. The linear regression analysis showed significant and positive relationship between N uptake and seed yield. Whereas, N uptake and utilization efficiency showed negative trend and decreased with increase in N uptake beyond 120?kg N/ha under normal N supply, and 60?kg N/ha under limited N supply. NUtE was positively correlated with seed yield under both normal as well as limited N supply. These results may be used to identify the key associated traits, and to isolate target genes for developing varieties/hybrids to harness better N economy.     

长期施用不同肥料对小麦玉米间作产量、氮吸收利用和土壤硝态氮累积的影响

对连续14年施用不同肥料后,春小麦.春玉米间作下,土壤硝态氮的累积和分布,作物产量及对氮素的吸收利用进行了研究。结果表明,在施农家肥120t.hm2(M)、绿肥45t.hm2(G)、秸杆10.5t.hm2(S)、N375kg.hm2(N)、农家肥60t.hm2+N187.5kg.hm2[1/2(M+N)]、绿肥22.5t.hm2+N187.5kg.hm2[1/2(G+N)]、秸杆5.25t.hm2+N187.5kg.hm2[1/2(S+N)]和CK等8个处理中,土壤剖面硝态氮的累积和分布以N处理最高,地上部N浓度和吸N量以N、1/2(M+N)和1/2(G+N)处理较高,但3处理间无明显差别。间作小麦子粒产量和生物学产量以M、G、1/2(M+N)和1/2(G+N)等处理较高,间作玉米子粒产量和生物学产量以1/2(G+N)、N、G和1/2(M+N)等处理较高。氮肥利用率以1/2(S+N)处理最高,1/2(M+N)和1/2(G+N)低于1/2(S+N)、S和N处理,但高于M、G处理。说明氮肥与农家肥或绿肥配合施用,既能增加作物产量,提高氮素吸收利用,又可减少土壤中硝态氮的累积。     

Water supply and growing season influence glucosinolate concentration and composition in turnip root (Brassica rapa ssp. rapifera L.)

The overall objective of this study was to determine whether growing season, water supply, and their interaction influence glucosinolate (GSL) concentration and composition in turnip roots (Brassica rapa ssp. rapifera L.). Field experiments on a loamy soil in Großbeeren, Germany, were conducted in the spring‐summer (SS), summer‐autumn (SA), and autumn‐winter (AW) growing seasons. Each experiment included three water‐supply treatments with 25%, 50%, and 75% of available soil water (ASW) as lower thresholds. We found that the total GSL concentration in turnip roots was 1774–3221 μmol (kg fresh matter [FM])^–1 and the dominant GSL was aromatic gluconasturtiin (GST) with concentrations of 1004–1628 μmol (kg FM)^–1 in turnip roots. Total, aliphatic, and some specific individual GSLs in turnip roots were significantly influenced by water supply, growing season, and their interaction, due to the variations of the root sulfur (S) concentration, climatic conditions, or both. The influence of water supply on GSL concentration was modified by growing season, which in turn influenced S concentration in turnips. In the SS season, the 25%‐ASW water treatment enhanced concentrations of total GSLs by 52% and 47%, aliphatic GSLs by 60% and 131%, and aromatic GSLs by 47% and 21% when compared to the 50%‐ and 75%‐ASW water treatments, respectively. No reduction of root yield was observed, although the shoot yield was reduced by limited water supply. In SA and AW, total GSL concentration did not change under different water‐supply levels, but concentration of individual aliphatic and indole GSLs did. Based on these results, growers can adjust their irrigation and S‐fertilization practices to growing season in order to optimize turnip quality in terms of GSL concentration and composition, while still obtaining higher root yield and enabling better resource utilization.     

灌溉条件下施氮水平对土壤 作物系统中肥料氮素去向的影响

本试验利用１５Ｎ示踪技术，研究３种施氮水平（适宜施氮量Ｎ１０∶１５０ｋｇＮ·ｈａ－１，低于适宜施氮量的５０％Ｎ０５∶７５ｋｇＮ·ｈａ－１，高于适宜施氮量的５０％Ｎ１５∶２２５ｋｇＮ·ｈａ－１）对灌溉冬小麦氮素利用、去向及作物产量的影响。结果表明：在灌溉条件下，３种施氮水平（Ｎ０５，Ｎ１０，Ｎ１５）的冬小麦氮素利用效率分别为３８５％、３２３％和２２４％，以Ｎ０５水平为最高。Ｎ１０施氮水平获得了最高的作物产量（６８０×１０３ｋｇ籽粒·ｈａ－１，１４７×１０３ｋｇ生物量·ｈａ－１），Ｎ０５水平同Ｎ１０水平相比，在产量上没有显著性差异；而Ｎ１５水平因施氮过量造成籽粒产量明显下降，与不施肥相比，差异不显著。在深层条施（５～８ｍｍ）条件下，仍有３０２％～３６７％的化学氮素通过各种途径而损失。在Ｎ１５水平中，施用氮素的４６％仍存在于０～５０ｃｍ土层中，远远高于其它两种施肥水平。土壤残留态的无机氮素含量以Ｎ１５施氮水平为最高     

Alterations in yield,physicochemical components and mineral composition of onion following organic manure and inorganic nitrogen application

Onion is the one of the most important vegetable crops grown extensively throughout the world; hence, understanding the response of the crop to the form and amount of N provided is of immense importance. In a field experiment, poultry and cattle manure (at 10?t/ha) were compared with four inorganic nitrogen (N) application levels (0, 60, 90 and 120?kg?N/ha), and six combinations of manure and N applications were investigated. Plant growth and total yield (kg/ha) significantly increased, when N application increased from 0 to 120?kg/ha, with or without added poultry manure. Plant height, leaf number and neck thickness were significantly reduced at 0?kg/ha?N plus cattle manure. The bulb ascorbic acid concentration significantly increased with the use of poultry manure (15.94?mg/100?g) and cattle manure (15.94?mg/100?g), compared with 120?kg/ha inorganic N (11.42?mg/100?g). No significant effects were observed on total phenolics and total soluble solids of onion bulbs following the different fertiliser treatments. Cattle manure increased P and K concentrations, whilst poultry manure significantly increased Zn and Fe concentrations in onion bulbs. Onion bulb Ca and Mg concentrations were lower when cattle manure (0.19% and 0.12%) was used than when other organic or inorganic fertilisers were used. Therefore, organic manure increases the concentrations of certain minerals in onions, compared with inorganic N application, without negatively affecting bulb size.     

东北黑土区大豆生长、结瘤及产量对氮、磷的响应

氮肥和磷肥显著影响大豆的结瘤和产量。然而在土壤肥力较高、速效养分有效性差的东北地区,有关氮肥和磷肥施用量对大豆结瘤和产量影响的研究较少。本试验采用裂区田间试验,设置3个氮（N）水平（0、20 和 50 kg/hm2）和 3 个磷（P）水平（0、 20 和 40 kg/hm2）,研究氮、 磷及其交互作用对大豆生长发育、 结瘤特征及产量的影响。结果表明, 单施氮肥大豆生物量和产量随着施氮量的增加而增加,而根瘤数量、 干重、 大小和结瘤指数呈逐渐下降的趋势。单施磷肥促进大豆生物量、 产量、 根瘤数量、 干重、 大小和结瘤指数的增加,但其增幅低于施氮处理下的增幅。氮磷对大豆生长和产量促进作用高于单施氮和单施磷处理,但差异不显著;氮磷处理下的根瘤数量、 干重、 大小和结瘤指数低于单施磷处理;氮磷处理下N2（N 50 kg/hm2）处理下的大豆根瘤数量、 干重、 大小和结瘤指数高于N1处理（N 20 kg/hm2）下的,随着施磷量的增加大豆根瘤数量、 干重、 大小和结瘤指数增加,施磷能够抵消氮对大豆根瘤产生和形成的抑制。氮、 磷及其交互作用对大豆根瘤的影响都是直接的,并且不是通过促进大豆生长间接促进的。因此氮和磷均是限制东北地区大豆结瘤和产量的因素,但氮是主导因素。若要获得大豆高产,氮肥施用量需要控制在50 kg/hm2,磷肥在40 kg/hm2;但若想最大的发挥大豆的结瘤固氮功能,那么应该不施或者减少氮肥的施用量到20 kg/hm2,磷肥仍在40 kg/hm2。     

Effect of differential N and S competition in inter- and sole cropping of Brassica species and lettuce on glucosinolate concentration

Field and greenhouse pot experiments were conducted to evaluate the potential to use intercropping as an alternative method to increase glucosinolates in Brassicas by manipulating nitrogen (N) and sulfur (S) balance by intercropping with lettuce (Lactuca sativa L. var. capitata). In both experiments, four combinations of N and S fertilization were used. In the field experiment no effect of intercropping on the total glucosinolate concentration was found as the growing lettuce was strongly inhibited by the presence of broccoli (Brassica oleracea L. var. italic). In contrast to this, in the pot experiment both total and individual glucosinolate concentrations in red leaf mustard (Brassica juncea L.) increased by intercropping. Fertilization treatments influenced glucosinolate concentrations in both experiments, and an interaction between N and S fertilization was noticed.     

Effect of Nitrogen Rates and Method of Nitrogen Application on Dry Matter Yield and some Characters of Sorghum-Sudangrass Hybrid

In this study, the effect of nitrogen (N) rates (0, 40, 80, 120, 160 and 200 kg N ha -1 ) and methods of N application (A 1 : all N at sowing; A 2 : no N at sowing, half N after the first cutting and the remaining half after the second cutting; A 3 : one-third N at sowing, one-third after the first cutting, and the last third after the second cutting) on dry matter (DM) yield and some characters of the sorghum-sudangrass hybrid was investigated. DM yield increased significantly from 27.0 g pot -1 (0 kg N ha -1 ) to 38.6 g pot -1 (120 kg N ha -1 ). Higher N rates continued to increase the number of tillers per plant -1 (except for 40 and 80 kg N ha -1 ). N rates have significant effect on crude protein (CP) content, and CP content varied from 6.71 to 7.08%. N up to 120 kg N ha -1 rate increased CP yield, but no difference was observed among 80, 120, 160 and 200 kg N ha -1 . There was no significant effect of the method of N application in terms of DM yield, tillering and CP yield. However, the method of N application had a significant effect on CP content, which was 7.09% by A 1 , 6.97% by A 2 and 6.57% by A 3 .     

不同轮作模式对太湖地区大棚菜地土壤氮淋失的影响

为控制太湖地区设施菜地氮素淋失,减小地下水污染风险,本研究选取2种轮作模式,即芹菜-番茄-莴苣（模式1）和金花菜-番茄-莴苣（模式2）,2种轮作模式下分别设置2个施氮量水平,即习惯施氮（N1）和减量施氮（N2）,研究不同轮作模式和施氮水平对设施菜地全年氮素淋洗的影响,并观测了不同轮作模式下土壤硝态氮含量、 电导率和pH的变化。结果表明,与模式1 相比,模式2可分别使N1和N2处理的淋洗液中的 NO-3-N 平均浓度降低了36%和38%,进而使全年总氮淋洗量减少了41% 和38%,但淋洗液体积不变。模式2 结合减量施氮（N2）对设施菜地氮素淋失阻控效果最佳,全年总氮淋失量为63.0 kg/hm2,而年经济效益最高,可达 51.9104 Yuan/hm2,最大经济效益提高29%。一年三季蔬菜收获后,N1处理下模式2的土壤硝态氮含量（020 cm）为189.2 mg/kg,而模式1的高达269.3 mg/kg。因此模式2可分别使N1和N2水平下的土壤硝态氮含量减少30% 和 26%,同时也显著降低了土壤pH和电导率（P＜0.05）。在太湖地区,选择需氮量较少的作物进行合理优化轮作（如金花菜-番茄-莴苣轮作模式）,是减少设施菜地氮素流失的有效手段,且具有较好的经济效益。