稻田水肥资源高效利用与调控模拟

水和肥是影响作物产量与生态环境的重要因素。为揭示稻田水肥利用规律,以达到稻田节水、省肥、高产、减排的目标,该文以湖北省漳河团林实验站稻田水肥耦合灌溉与控制排水试验观测数据为基础,联合运用作物生长模型ORYZA 2000和田间水文模型DRAINMOD 6.0,模拟分析不同降水、节灌、施肥、控排条件下的水稻产量与稻田排水量响应关系,得出了稻田水肥调控的临界条件,即采用稻田间歇灌溉方式,灌水定额30 mm,施氮量170 kg/hm2左右,控制排水水位20 cm时,节水12.5%～18.87%、省肥35.1%、增产11%、减排19.9%。本研究对加强农田水肥科学管理,提高水氮生产效率,防治农业面源污染,促进灌区可持续发展具有重要意义。     

菜园土壤不同施肥模式下小青菜生长和品质及其生态化学计量学特征

利用盆栽试验研究了不同施肥处理对小青菜生长和品质的影响,并在此基础上利用生态化学计量学方法研究了小青菜生长和品质与其生态化学计量学特征之间的相关关系。结果表明在盆栽的条件下施氮量为180kg/hm2是小青菜生长较为合适的水平,能达到节氮保产的效果。在氮水平为180kg/hm2下,有机无机肥配施模式1(含有氨基酸肥料)提高了小青菜地上部的生长、碳浓度、光合速率、可溶性总糖、蔗糖、游离氨基酸含量和根系鲜重,且这些指标与其地上部C/N(碳氮比)和C/P(碳磷比)之间存在显著正相关关系,而与施肥模式中C/N和C/P之间存在正相关趋势,但相关关系不显著。此外,有机无机肥配施模式1降低了小青菜的地上部硝酸盐含量,且该指标与其地上部和施肥模式中N/P(氮磷比)、C/N、C/P和P/K(磷钾比)之间均不存在相关关系。因此,有机无机肥配施模式1促进了小青菜地上部和根系生长,提高了光合速率,改善了小青菜地上部的品质,是一种科学的施肥措施。     

微咸水加肥灌溉下陶瓷灌水器与迷宫流道灌水器的抗堵塞性能

为探求微孔陶瓷灌水器与迷宫流道灌水器在不同水质灌溉条件下抗堵塞性能的差异及堵塞机理,该研究选择了微咸水(A1)、肥水(A2)、微咸水加肥(A3)3种不同水质,分析管间式微孔陶瓷灌水器和6种常用的迷宫流道灌水器在不同水质灌溉条件下的平均相对流量变化规律,并用X射线衍射仪测定堵塞物质组成成分,用场发射扫描电镜观测堵塞物质表面微观形貌及动态生长过程。结果表明：各灌水器的流量随着灌溉运行时间的推移均发生不同程度的下降,其中A1处理下陶瓷灌水器的流量下降最慢,表现出优于迷宫流道灌水器的抗堵塞性能,A2、A3处理下陶瓷灌水器的平均相对流量下降速度先慢后快,试验结束时平均相对流量降幅最大,抗堵塞性能较差;A1处理下堵塞物质的主要成分是CaCO3,A2、A3处理下堵塞物质的主要成分是(NH4)2SO4;A1处理下各灌水器堵塞物表面微观形貌的生长过程为晶体颗粒不断团聚,A2、A3处理下堵塞物的动态生长过程为絮状物不断黏合成板块状或膜状。陶瓷灌水器堵塞发生在内壁上,堵塞物未进入到灌水器内部微孔中,随着堵塞物质增多且变得紧密复杂逐渐覆盖了内壁上的孔隙导致堵塞;迷宫流道灌水器是由于堵塞物质在流道内沉积导致过水断面减小,从而造成堵塞。研究结果可为陶瓷灌水器的应用及改进提供参考     

基施磷肥对石灰性土壤上番茄产量的影响

A lysimeter experiment with undisturbed soil profiles was carried out to study nitrogen cycling and losses in a paddy soll with applications of coated urea and urea under a rice-wheat rotation system in the Taihu Lake region from 2001 to 2003. Treatments for rice and wheat included urea at conventional, 300 （rice） and 250 （wheat） kg N ha^-1, and reduced levels, 150 （rice） and 125 （wheat） kg N ha^-1, coated urea at two levels, 100 （rice） and 75 （wheat） kg N ha^-1, and 150 （rice） and 125 （wheat） kg N ha^-1, and a control with no nitrogen arranged in a completely randomized design. The results under two rice-wheat rotations showed that N losses through both NH3 volatilization and runoff in the coated urea treatments were much lower than those in the urea treatments. In the urea treatments N runoff losses were significantly （P 〈 0.001） positively correlated （r = 0.851） with applied N. N concentration in surface water increased rapidly to maximum two days after urea application and then decreased quickly. However, if there was no heavy rain within five days of fertilizer application, the likelihood of N loss by runoff was not high. As the treatments showed little difference in N loss via percolation, nitrate N in the groundwater of the paddy fields was not directly related to N leaching. The total yield of the two rice-wheat rotations in the treatment of coated urea at 50% conventional level was higher than that in the treatment of urea at the conventional level. Thus, coated urea was more favorable to rice production and environmental protection than urea.     

Effect of long-term manuring and fertilizers on carbon pools,soil structure,and sustainability under different cropping systems in wet-temperate zone of northwest Himalayas

We investigated C management index (CMI; an indicator of sustainability of a management system and is based on total and labile C) and soil aggregation in medium-textured soils (silt loam and silty clay loam) under different cropping systems as follows: maize-wheat (M-W), rice-wheat (R-W), soybean-wheat (S-W), Guinea grass, and Setaria grass. Field experiments were 6–32 years long and were located in the wet-temperate zone of northwest Himalayas. The plant nutrients were applied through chemical fertilizers (urea, superphosphate, and muriate of potash) with or without organic materials (FYM, wheat straw, and Lantana spp.). The content of total C (C_T), labile C (C_L), CMI, mean weight diameter (MWD), and aggregate porosity varied significantly under different cropping systems. The range was 1.59 (R-W)–4.29% (Setaria) for C_T, 1.23 (R-W)–3.89 mg/kg (Guinea grass) for C_L, 52.09 (R-W)–129.77 (Guinea grass) for CMI, 0.90 (R-W)–5.09 (Guinea grass) for MWD, and 41.5 (R-W)–56.8% (S-W) for aggregate porosity. Aggregate porosity was highest (56.8%) under S-W, followed by grasses (50.1–51.2%), and M/R-W (41.5–50.0%). As per these data, (a) continuous use of N alone as urea lowered soil sustainability over control (no fertilizers); (b) use of NPK at recommended rates improved soil productivity over control; (c) the NPK + organic amendments further improved soil sustainability; and (d) the sustainability under different cropping systems followed the order: perennial grasses > soybean-wheat > maize-wheat > rice-wheat.     

配施硫基肥对夏玉米镉铅累积的阻控效应

该文以府河流域污灌区农田为研究对象,通过田间小区试验研究了5种施肥措施对土壤重金属镉(Cd)、铅(Pb)有效性以及夏玉米(Zea mays L.)对Cd、Pb富集和转运能力的影响。结果表明:与农民常规施肥(CK)相比,尿素、磷酸二铵和氯化钾配施(N-P-K)以及腐殖酸复合肥、尿素和磷酸二铵配施(HA-N-P)的表层土壤Cd、Pb有效性以及夏玉米对Cd、Pb的富集和迁移能力差异均不显著(P0.05)。然而,腐殖酸复合肥、硫酸铵和磷酸二铵配施(HA-S-P)以及硫酸铵、磷酸二铵和硫酸钾配施(S-P-K)2种施肥措施的表层土壤有效Cd含量分别比CK降低了10.60%和6.36%,表层土壤有效Pb含量分别比CK降低了11.49%和6.00%。此外,HA-S-P处理和S-P-K处理夏玉米Pb转运系数分别比CK降低了50.33%和77.10%,且夏玉米籽粒Pb含量分别比CK降低了59.75%和80.43%(P0.05),但各处理间夏玉米对Cd的转运和富集能力差异并不显著,这说明施用硫基肥可有效抑制夏玉米对Pb的富集和转运,但并未影响其对Cd的富集和转运。综上所述,该污灌区轻度Cd、Pb复合污染农田土壤种植夏玉米建议硫酸铵、磷酸二铵和硫酸钾配施,或者腐殖酸复合肥、硫酸铵和磷酸二铵配施。     

氮肥与氮转化调控剂配施降低夏玉米-冬小麦农田N2O排放

针对农业生产中氮肥施用不合理导致氮肥利用率低、N_2O排放增加及经济效益下降等问题,采用田间试验法研究了不同氮肥与氮转化调控剂配施模式的夏玉米-冬小麦一年两作农田N_2O排放特征及经济效益。结果表明:与农民施氮肥处理(FN)相比,各推荐施氮处理在夏玉米季和冬小麦季的N_2O平均排放通量分别降低29.2%~65.4%(P0.05)和26.9%~74.9%(P0.05),N_2O排放总量分别降低1.05~2.72(P0.05)和1.10~2.47(P0.05)kg/hm~2;整个轮作季纯收益增加967.5~3 887.0元/hm~2。同等施氮量条件下,与推荐施氮处理(RN)相比,夏玉米季推荐施氮配施双氰胺处理(RN+DCD)和推荐施氮配施吡啶处理(RN+CP)分别使N_2O平均排放通量降低41.5%(P0.05)和31.2%(P0.05);而在冬小麦季则分别下降63.0%(P0.05)和65.7%(P0.05);整个轮作季RN+DCD和RN+CP处理N_2O排放总量分别降低了52.5%(P0.05)和49.0%(P0.05),纯收益分别增加312.6和708.9元/hm~2。夏玉米季,土壤N_2O阶段排放峰值出现在三叶期-拔节期和大喇叭口期-抽雄期;而冬小麦季土壤N_2O阶段排放峰值出现在播种-冬前苗期和返青-拔节期。考虑作物产量、N_2O排放以及经济效益,RN+DCD和RN+CP处理经济效益较高,N_2O排放总量较少,是兼顾作物产量、农民收入及大气环境的推荐氮肥管理措施。     

不同配比有机无机肥料对菜地N2O排放的影响

【目的】 采用静态暗箱-气相色谱法,研究有机无机肥料配施对菜地N₂O排放的影响。【方法】 试验期间连续种植了4季蔬菜,分别为香菜、空心菜、菜秧、菠菜,其中香菜和菠菜种植期间有塑料大棚覆盖。每季蔬菜收获后至下季蔬菜种植前有时间不等的休耕期。每季蔬菜种植前肥料作为基肥一次性施入,施肥量均为N 250 kg/hm2,其中空心菜在第二茬收获后追施N 250 kg/hm2一次,整个观测期共施肥5次,总施氮量为N 1250 kg/hm2,同时施入等量P₂O₅、K₂O。试验共设4个处理:不施氮对照（CK）、单施化肥（NPK）、有机无机肥料1:1配施（M1N1）和有机无机肥料2:1配施（M2N1）。N₂O排放通量测定频率为每周一次,每次施肥后则每2天测定一次。【结果】 观测期内各处理菜地N₂O排放主要集中在4~10月份,并与10 cm土层土壤温度呈显著正相关;NPK处理菜地N₂O排放通量与土壤无机氮含量显著相关,其他处理N₂O排放通量与土壤铵态氮、硝态氮以及无机氮含量间无显著相关。整个观测期内土壤充水孔隙度（WFPS）介于39%~59%之间,土壤水分含量的变化对N₂O排放通量无显著影响。与NPK处理相比,M1N1和M2N1处理均能保证蔬菜产量稳定,并显著提高空心菜的产量。与NPK处理相比,M1N1处理显著降低菜地N₂O周年累积排放量36%,显著降低N₂O周年排放系数64%。与M2N1处理相比,M1N1处理的N₂O周年累积排放量和周年排放系数分别显著降低29%和56%;而M2N1处理较NPK处理的减排效果不显著。【结论】 在集约化菜地适宜的无机有机肥料配比既能保证蔬菜产量,又能减少N₂O排放,不施或施用有机肥比例过高均不利于减少N₂O周年排放。本试验条件下,有机无机肥料以1:1配施是合适的稳产减排措施。     

Nutrients management strategies to improve yield and quality of sugar beet in semi-arid regions

The objective of this study was to evaluate the effects of organic and inorganic fertilizers on the yield and quality of sugar beet genotypes (Beta vulgaris L.). Therefore, a field trial was carried out in Peshawar, Pakistan, during the winters in 2012–2013. The field experiment was conducted in a randomized complete block design with split plots, having three replications. Fertilizer treatments (control, composted manure Higo Organic Plus at 5 t ha^?1, Maxicrop Sea Gold seaweed extract at 5 L ha^?1, farm yard manure at 10 t ha^?1, inorganic nitrogen–phosphorus (NP) at 90:60 kg ha^?1, NP at 120:90 kg ha^?1 and NP at 150:120 kg ha^?1) were allotted to main plots, while genotypes (Sandrina, Serenada and Kawe Terma) were allotted to the sub-plots. Plots treated with the application of NP at 120:90 kg ha^?1 produced the highest beet yield (76.4 t ha^?1) and sugar yield (11.1 t ha^?1), and had the second highest polarizable sugar content (14.52%) and more economic return (Rs. 553,000 per hectare) as compared to control plots. Sugar beet genotype Serenada had significantly higher beet yield (55.5 t ha^?1) and sugar yield (7.9 t ha^?1) and a higher economic return (Rs. 380,000 per hectare) than the other genotypes. Sugar beet genotype Serenada supplied with NP at 120:90 kg ha^?1is recommended for the general cultivation in the agro-climatic conditions of Peshawar valley.     

Influence of compost/sludge application on sugarcane yield and nitrogen requirement on a sand soil

Mineral soils in southern Florida are very low in organic matter content and most of the nitrogen (N) for sugarcane (Saccharum spp.) must be supplied in split fertilizer applications. Information is needed regarding how the interaction of organic amendments and fertilizer N influences sugarcane yields. A field study on a sand soil (Alfisol) was established to determine (1) potential sugarcane yield benefits of a compost/sludge amendment, and (2) the influence of the amendment on N fertilizer requirement. A split-plot Latin square design was used with five N rates (main plots) and presence or absence of compost/sludge broadcast at 113 m³ ha^?1 (subplots). Annual N rates were 0, 67, 134, 202, and 269 kg N ha^?1. Compost/sludge application increased cumulative t sucrose ha^?1 by 36% averaged across N rates. The amendment also lowered annual N requirement by an average of 38%, but maintenance applications of compost/sludge will be required every four years.