Impact of organic and inorganic fertilizers on yield,taste, and nutritional quality of tomatoes

In a greenhouse experiment, tomato plants were grown in sand culture to test whether different fertilization regimes (mineral or organic fertilizers) at low (500 mg N plant^–1 week^–1) and high (750 mg N plant^–1 week^–1) nitrogen levels affected yield, nutritional quality, and taste of the fruits. In the mineral‐fertilizer treatments, nitrate‐ or ammonium‐dominated nutrient solutions were used. Organic fertilizer was supplied as fresh cut grass‐clover mulch (a total of 2.4 kg and 3.6 kg were given per plant at low and high N level, respectively) without (orgN) and with additional sulfur fertilization (orgN+S). Yields of red tomatoes from the organically fertilized plants were significantly lower (1.3–1.8 kg plant^–1) than yields from plants that received mineral fertilizer (2.2–2.8 kg plant^–1). At the final harvest, yields of green tomatoes in the organic treatment with extra sulfur were similar (1.1–1.2 kg plant^–1) to the NO ‐dominated treatments at both nutrient levels and the NH ‐dominated treatment at high nutrient level. Organic fertilizers released nutrients more slowly than mineral fertilizers, resulting in decreased S and P concentrations in the leaves, which limited growth and yield in the orgN treatments. Analysis of tomato fruits and plants as well as taste‐test results gave no conclusive answer on the relationship between sugar or acid contents in the fruits, macronutrient content of plant leaves and fruits, and perceived taste. Sugar contents were higher in the fruits given mineral fertilizer, whereas acid contents were higher in the fruits given organic fertilizer. Preference in taste was given to the tomatoes from plants fertilized with the nitrate‐dominated nutrient solution and to those given organic fertilizer with extra sulfur. Thus, a reduction in growth, which was expected to lead to a higher concentration of compounds like sugars and acids, did not result in better taste. Overall, it can be concluded that an appropriate nutrient supply is crucial to reach high yields and good taste.     

硝基复合肥对马铃薯生长发育、产量及品质的影响

通过大田试验,研究了不同硝基肥品种对马铃薯生长发育、产量及品质的影响。结果表明,在氮磷钾等量的条件下,施用硝硫基复合肥和硝氯基复合肥较氯基复合肥、硫基复合肥能明显地促进马铃薯生长发育,增加单薯重、单株重以及肥料利用率。与硝氯基复合肥、硫基复合肥和氯基复合肥处理相比,施用硝硫基复合肥处理的马铃薯增产率分别为2.96%~3.06%、5.19%~5.51%和10.05%~10.37%;同时能够改善马铃薯的果实品质,增加果实的淀粉、可溶性糖和Vc含量,是较为理想的复合肥。     

有机-无机缓释肥对番茄产量和氮肥利用率的影响

利用盆栽试验研究了有机-无机缓释肥料对番茄产量和氮肥利用率的影响。结果表明,与施用等NPK无机养分对照比较,施用缓释肥料B显著提高氮肥利用率,增加肥料氮在果实和叶片中的分配率;并且有利于后期产量形成,增产17.13%。施用缓释肥料A2提高氮肥利用率,增加肥料氮在根系和叶片中的分配率;并且有利于后期产量形成,增产16.33%。施用缓释肥料A2,氮肥利用率和产量的增幅均较小。     

有机肥无机肥配施对温室黄瓜生长、 产量和品质的影响

蔬菜生产过量使用有机肥也会影响蔬菜的生长、 降低蔬菜的品质。本项目在保护地栽培条件下,研究了一定养分量投入中,在黄瓜上有机肥和无机肥的最佳配比。试验采用泡沫槽栽培,所有供试肥料均以底肥形式一次性施入。结果表明,施有机肥30 t/hm2+无机肥0.9 t/hm2的处理和施有机肥45 t/hm2+无机肥0.45 t/hm2的处理严重抑制了黄瓜定植初期的生长,降低了前期单株产量和果实中Vc、 可溶性糖含量,增加了硝酸盐含量。单施有机肥60 t/hm2的处理肥害相对较轻,植株恢复生长较快。单施无机肥1.8 t/hm2的处理和施有机肥15 t/hm2+无机肥1.35 t/hm2的处理植株生长势强,前期单株产量、 果实中Vc、 可溶性蛋白和可溶性糖含量较高,硝酸盐积累量较低,但这两个处理在结果后期发生早衰,导致中后期产量下降。综合生长、 产量和品质指标,最优的底肥组合应该是施有机肥15 t/hm2+无机肥1.35 t/hm2的处理,但要注意生长中后期进行追肥,以满足果实生长的营养需求,以期获得较高的产量。     

Nitrogen forms affect root growth,photosynthesis, and yield of tomato under alternate partial root‐zone irrigation

To increase efficiency of water and nitrogen (N) fertilizer use, this study was conducted with a split‐root pot experiment to investigate the effects of different forms of N fertilizer on root growth, photosynthesis, instantaneous water use efficiency (IWUE), and yield of tomato (Lycopersicon esculentum L.) under alternate partial root‐zone irrigation (APRI). Three irrigation modes comprised conventional irrigation (CI) and two kinds of APRI, i.e., APRI with water content in the drying soil compartment controlled at ≥ 60% or 40% of the water‐holding capacity (APRI‐60, APRI‐40). Two N forms included ammonium‐N and nitrate‐N supplied as calcium nitrate or ammonium sulfate, respectively. The results show that APRI‐60 enhanced root growth and increased leaf IWUE with a slight yield reduction compared with CI regardless of the N form supplied. In contrast, APRI‐40 significantly decreased root growth and inhibited photosynthesis, thereby resulting in a significant yield loss. In addition, at the flowering stage tomato plants grew better with ammonium‐N than nitrate‐N supply; however, at the fruit expansion stage and maturity stage, the tomato plants had a higher biomass accumulation and yield with nitrate‐N than ammonium‐N supply. Therefore, the application of APRI should consider the soil water condition coupled with an appropriate N form. In the present study, APRI controlled at ≥ 60% of the water‐holding capacity (WHC) for the drying soil side with nitrate‐N supply was the best water‐fertilizer supply for tomato cultivation.     

Short‐term and residual availability of nitrogen after long‐term application of organic fertilizers on arable land

Knowledge on short‐term and long‐term availability of nitrogen (N) after application of organic fertilizers (e.g., farmyard manure, slurry, sewage sludge, composts) provides an important basis to optimize fertilizer use with benefits for the farmer and the environment. Nitrogen from many organic fertilizers often shows little effect on crop growth in the year of application, because of the slow‐release characteristics of organically bound N. Furthermore, N immobilization after application can occur, leading to an enrichment of the soil N pool. However, this process finally increases the long‐term efficiency of organic fertilizers. Short‐term N release from organic fertilizers, measured as mineral‐fertilizer equivalents (MFE), varies greatly from 0% (some composts) to nearly 100% (urine). The most important indicators to be used for predicting the short‐term availability of N are total and NH ‐N contents, C : N ratio (especially of the decomposable organic fraction), and stability of the organic substances. Processing steps before organic fertilizers are applied in the field particularly can influence N availability. Composting reduces mineral‐N content and increases the stability of the organic matter, whereas anaerobic fermentation increases NH ‐N content as well as the stability of organic matter, but decreases the C : N ratio remarkably, resulting in a product with a high content of directly available N. Nevertheless, long‐term effects of organic fertilizers rather slowly releasing N have to be considered to enable optimization of fertilizer use. After long‐term application of organic fertilizers, the overall N‐use efficiency is adequate to a MFE in the range of 40%–70%.     

有机-无机肥配施对水稻产量、品质及氮素吸收的影响

通过田间试验,研究氮施用量相同的条件下,有机肥和化肥不同比例（有机肥氮分别占100%、70%、40%、20%和0%）,对早稻、晚稻及单季稻施用对水稻产量、品质和氮素吸收的影响。结果表明,有机肥氮为40%、20%、40%时,早稻、晚稻和单季稻产量最高,分别比单施化肥区增8.5%、2.8%和4.6%。有机肥氮在20%～40%之间,稻米品质较佳,比例过高则稻米易碎、垩白上升和蛋白质含量下降。有机肥氮为20%水稻氮素累积量最高,有利于氮素的吸收、利用。     

成都平原露地番茄施用钙、镁、锌、锰肥的效应

试验以成都平原露地番茄为研究对象,对中量元素肥料钙、镁及微量元素肥料锰、锌的施用效果进行了初步的研究。结果表明,Ca、Mg和Zn配合施用可使番茄产量增加10.0%以上;硝酸盐含量只有NPK处理的80.0%左右,Vc含量增加42.6%,糖酸比和固酸比增加;种植效益可增加10.0%以上。Mn对于增加番茄的产量、改善其品质的效果不明显。综合来看,Ca、Mg和Zn是成都平原露地番茄生长的营养障碍因子,且三者配合施用的效果优于单独施用。     

有机无机肥配施对大白菜产量、品质及重金属含量的影响

以大白菜为试材,进行了有机肥与无机肥不同配比施用对大白菜产量、营养品质、安全品质以及重金属含量的影响研究。结果表明,在施氮量相同条件下,有机肥与无机肥配施可以提高大白菜的营养品质、安全品质和产量,综合评价以有机肥与无机肥质量分数为4∶6时的效应最佳。大白菜硝酸盐含量随无机肥配施比例增加而提高,相关性达到极显著水平;各处理大白菜亚硝酸盐含量差异不显著。不同施肥处理对大白菜中Cu、Zn和Cd含量的影响作用较小;施肥处理可使大白菜中Pb含量显著低于不施肥处理,有机肥和无机肥处理分别降低了24.3%和16.2%;施用有机肥比不施肥处理的As和Hg含量分别增加26.4%和21.1%;无机肥处理使大白菜Cr、As和Hg含量分别增加19.0%、16.2%和174.3%,特别是随无机肥配施量的增加有使Hg含量提高的趋势。     

微生物菌肥菌剂对番茄生长发育和产量品质的影响

为了探究微生物菌肥和微生物菌剂对番茄生长发育和产量品质的影响,以“桃星”番茄为试验对象,设置普通商品有机肥+灭菌后的微生物菌剂(CK)、普通商品有机肥+微生物菌剂(T1)、微生物菌肥+灭菌后的微生物菌剂(T2)、微生物菌肥+微生物菌剂(T3)4个处理。在膨果初期测定番茄植株株高、茎粗和叶片SPAD值,膨果期计算番茄每层膨果挂果数、产量和品质(可溶性固形物、可滴定酸、糖酸比和Vc含量)。结果表明,微生物菌肥能显著地促进番茄植株生长发育,施用微生物菌肥的处理(T2和T3)的植株茎粗均达到13 mm以上,株高比对照(CK)稍有增加;微生物菌肥+微生物菌剂(T3)增产效果最好,总产量较对照(CK)提高13.6%;第3-5膨果期果实的可溶性固形物较对照分别提高了3.21%,3.87%和4.55%,糖酸比分别较对照提高了7.63%,10.1%和12.9%,Vc含量分别较对照提高了6.27%、7.67%和8.10%。综上,施用微生物菌肥和菌剂能促进番茄植株生长,增加番茄产量,提高果实品质,对产量和品质的促进作用在番茄挂果期的中后期表现出来。     

不同有机肥处理对黄冠梨生长及果园土壤性状的影响

为探明不同有机肥对梨树生长和果园土壤生物性状的影响,通过田间小区试验研究了不施肥处理(CK)、传统施肥(TF)、生物有机肥(BOF)、鸡粪堆肥(CM)及有机无机复混肥(CF)对黄冠梨树地上部生长、产量和品质、土壤微生物量碳氮和矿质态氮含量动态变化的影响.结果表明,(1)各处理均增加了叶面积、百叶重及新梢长度,果实可溶性固形物、可溶性糖含量和糖酸比也有不同程度提高,其中BOF处理效果最好,与CK相比BOF处理单果重和产量分别增加了17.4％和33.9％;(2)与CK和TF相比,其它有机肥处理在整个生育期均增加了土壤微生物数量及微生物量碳氮含量,且两者呈先增加后下降趋势;(3)梨园土壤中的矿质态氮以硝态氮为主,从萌芽期至二次膨大期各施肥处理矿质态氮含量逐渐下降,降幅为78.9％～88.7％,成熟期BOF处理的土壤矿质态氮含量高于其它处理.可见,施用有机肥可以促进树体生长,提高土壤微生物数量,改善土壤供氮特性.     

基于土壤电导率控制的养分供给对设施番茄生长、产量和品质的影响

我国设施蔬菜生产中缺乏有效决策指标来引导养分的科学投入,过量施肥已成为设施农业可持续发展的主要瓶颈。选用土壤电导率（EC）作为控制养分投入的决策指标,探索不同土壤EC对番茄生长、产量以及品质的影响,为未来智能化设施生产提供科学依据。通过在设施番茄体系实地试验,运用可视化电导率传感器对土壤进行实时监测,并结合水肥一体化设备进行养分投入,通过测定不同土壤EC对应的番茄生长、产量以及品质指标来分析最适合番茄生长的土壤EC。结果表明,番茄的株高、茎粗、叶片SPAD值等指标与土壤EC呈二次曲线关系,通过营养生长末期建立的二次曲线拟合得出株高在EC为4.03 mS/cm时达到最大值,茎粗和叶片SPAD值分别在EC为2.93和2.54 mS/cm时达到最大值;干物质累积量和产量也与土壤EC呈二次曲线关系,通过模型拟合得出番茄干物质累积量在EC为2.97 mS/cm时达到最大值,单果重在EC为3.19 mS/cm时达到最大值;外形品质和营养品质多个指标也与土壤EC呈二次曲线关系,模拟结果显示番茄商品果率在EC为2.77 mS/cm时达到最大值,番茄可溶性糖、有机酸、维生素C分别在EC为2.94、3.1...     

盐碱地条件下施氮量和栽插密度对水稻产量和品质的影响

在盐碱地条件下,以南粳9108为材料,设置6个施氮水平和2个移栽密度,研究施氮量和移栽密度对盐碱地条件下水稻产量和品质的影响。结果表明,随着施氮量的增加,产量呈现先上升后下降的趋势,低氮处理下,密度大的产量高,高氮处理则相反。施氮量的增加提高了单位面积穗数和每穗粒数并降低了结实率和千粒重,密度的提高增加了单位面积穗数。施氮量的增加在提升稻米碾磨品质的同时降低了外观品质和蒸煮食味品质,移栽密度对稻米品质影响不大。在每公顷施氮300 kg,移栽密度为12 cm×25 cm时,可以获得相对优质的最高产量。     

不同氮源与镁配施对甘蓝产量、品质和养分吸收的影响

采用田间试验和室内分析相结合的方法,研究不同氮源与镁配施对甘蓝(Brassica oleracea L.)产量、品质和养分吸收的影响。试验在等氮条件下设4个氮源,分别为不施氮肥、100%铵态氮、50%铵态氮+50%硝态氮、100%硝态氮;设4个硫酸镁施用量,分别为0、75 kg·hm-2、150 kg·hm-2、300 kg·hm-2。结果表明,100%硝态氮与中量(150 kg·hm-2)镁配施处理的甘蓝产量比不施肥处理、100%铵态氮与中量镁配施处理和50%铵态氮+50%硝态氮与中量镁配施处理分别增产56.9%、14.7%和5.2%。施用100%硝态氮处理的甘蓝产量略高于50%硝态氮+50%铵态氮处理,比施用100%铵态氮处理和不施肥处理分别增产13.0%和44.2%。施用低量(75kg·hm-2)镁肥的甘蓝产量比不施镁肥增产9.3%,而增加镁肥用量对甘蓝产量没有显著影响。施用100%硝态氮、50%铵态氮+50%硝态氮和100%铵态氮处理的甘蓝硝酸盐含量比不施氮肥处理分别增加84.4%、63.4%和6.9%。100%硝态氮与高量(300 kg·hm-2)镁肥配合施用的甘蓝硝酸盐含量比不施肥处理、100%铵态氮与高量镁肥配施处理和50%铵态氮+50%硝态氮与高镁肥配施处理分别增加101.4%、82.3%和14.1%。施用高量镁肥处理甘蓝硝酸盐含量比不施肥处理增加11.2%。随着硝态氮比例增加,甘蓝维生素C、还原糖、总氨基酸含量相应增加,镁肥施用量对甘蓝维生素C、还原糖、总氨基酸含量影响明显。随着硝态氮比例增加,甘蓝对磷、钾和钙吸收量显著增加;随着镁施用量增加,磷、钾和镁吸收量相应增加。不同氮源与镁肥相互作用对甘蓝维生素C含量,氮、磷、钾、钙和镁养分吸收均有明显的影响。本研究表明,50%硝态氮和50%铵态氮混合与适量镁肥配合施用,既能增加甘蓝产量,提高维生素C、还原糖和总氨基酸含量,又能减少硝酸盐含量,提高甘蓝品质。     

Effects of lime and sewage sludge on soil,pasture production,and tree growth in a six‐year‐old Populus canadensis Moench silvopastoral system

In many regions worldwide, silvopastoral systems are implemented to enable sustainable land use allowing short, medium, and long‐term economic returns. However, the short‐term production in silvopastoral systems is often limited due to nonappropriate soil‐fertility management. This study evaluated the effects of two doses of lime (0 and 2.5 t CaCO₃ ha^–1) and three sewage‐sludge treatments (0, 200, and 400 kg total N ha^–1 y^–1 applied in 2 consecutive years) on soil characteristics (soil pH, soil organic matter [SOM], soil nitrogen, cation‐exchange capacity [CEC]), pasture production, and tree growth in a silvopastoral system of Populus × canadensis Moench in Galicia, northern Spain during 6 years after establishment. Soil pH increased during the experimental period for all treatments, although this effect was more pronounced after lime application. Changes in SOM and soil nitrogen content were not consistent over time, but sewage‐sludge application seemed to result in higher values. Higher CEC was found for treatments with lime and sewage‐sludge application. Following incorporation of lime and sewage sludge, pasture production was significantly enhanced (cumulative pasture production 51.9 t DM ha^–1 for Lime/N400 compared to 39.0 t DM ha^–1 for No lime/N0). This higher pasture production also affected tree growth due to more severe competition between pasture and tree resulting in slower tree growth. Liming and application of sewage sludge are relevant measures to improve soil fertility and thereby optimizing the overall production of silvopastoral systems. However, it is important not to overintensify pasture production to ensure adequate tree growth.     

Long‐term effects of animal manure and mineral fertilizers on phosphorus availability and silage maize growth

A better appraisal of the plant availability of soil phosphorus (P) added with animal manure is crucial to alleviate environmental impacts from over‐application of P. This study compares the availability of P to maize in the Askov long‐term experiments using unmanured plots and plots receiving corresponding rates of nitrogen (N), P and potassium (K) in mineral fertilizers or manure. Total‐P and water extractable P (Pw) in soil, and plant height, dry weight, P concentration and P uptake were determined in early August. Final yields were determined in late October. Soil Pw was similar for plots receiving corresponding rates of P in mineral fertilizer or manure form. With a strong relationship between Pw, and maize growth and final yields, Pw was a reliable indicator of P availability to maize. Plant dry weight, P concentration and P uptake in early August were 23%, 8% and 31% higher, respectively, for maize grown on soil receiving manure compared with mineral fertilizer, while final maize yield in late October was 13% higher. Plant height and dry weight determined in early August suggested that maize development at this growth stage defined final maize yield. We conclude that the availability of P was similar after long‐term application of corresponding rates of P in animal manure and mineral fertilizers, and that animal manure improves the growth of maize compared to mineral fertilizers. This is ascribed to micronutrients and residual N effects from previous additions of manure.     

不同有机物及其堆肥与化肥配施对小麦生长及氮素吸收的影响

采用15N示踪技术,选用水稻土和灰潮土在宜兴进行小麦盆栽试验,研究了稻草、猪粪及其堆肥与化肥配施对作物生长及氮素吸收的影响。结果表明,在水稻土和灰潮土上,不同有机物及其堆肥与化肥配施分别比单施化肥增产4.46%～24.82%和1.01%～20.53%,稻草堆肥和猪粪堆肥配施化肥处理籽粒产量分别高于稻草和猪粪直接与化肥配施处理。稻草和猪粪堆肥后更利于作物吸收氮素,增加植物体内15N累积。两种土壤上15N回收率表现为相同配比的堆肥处理未堆肥处理单施化肥处理。随着小麦生育期的推进,土壤微生物量氮和矿质态氮含量均呈下降趋势,稻草和猪粪处理的微生量氮含量始终高于稻草堆肥和猪粪堆肥处理。有机无机肥配施处理土壤矿质态氮在小麦生育前期低于单施化肥,成熟期则高于单施化肥。整个生育期中,稻草堆肥和猪粪堆肥处理土壤矿质态氮含量分别高于稻草和猪粪处理。因此,有机物堆肥后与化肥配施更有利于提高产量,促进作物对氮素的吸收利用。     

Influence of fertilization and organic amendments on organic‐carbon fractions in Heilu soil on the loess plateau of China

The influence of fertilization on organic‐carbon fractions separated by density and particle size in Heilu soil (Calcic Kastanozems, FAO) was investigated in a 20‐year (1979–1999) long‐term experiment on the Loess Plateau of China. Compared to an unfertilized treatment, N application alone did not increase total organic carbon (TOC) and its fractions of density and particle size. However, the treatment of N + P fertilization significantly increased salty‐solution–soluble organic carbon (SSOC), microbial biomass C (MB‐C), and organic C associated with fine silt. When manure was applied alone and in combination with N and P fertilizer, the light fraction of organic C (LFOC), SSOC, and MB‐C were increased significantly, and the TOC was as high as that of a native Heilu soil. Organic C associated with different particle‐size fractions was also increased significantly, and the allocation of C among the fractions was altered: the proportions of C in sand (>50 μm), coarse‐silt (20–50 μm), and fine‐clay (<0.2 μm) fractions were increased whereas fine‐silt (2–20 μm) and coarse‐clay (0.2–2 μm) fractions were decreased. It is concluded that N fertilizer alone is not capable of restoring organic‐matter content in the Heilu soils of the Loess Plateau and that C‐containing material like manure and straw is necessary to produce significant increase in soil organic carbon in these soils.     

Effects of buckwheat growth on variation of aluminum and major metals in root‐zone soil solutions

The variation in and relationships between aluminum and other major metals including Ca, Mg, Mn, and K in root‐zone soil solutions were studied by growing buckwheat (Fagopyrum esculentum Moench. cv. Jiangxi), an Al accumulator, in pots filled with an acid soil amended with CaCO₃ and unamended controls with a preinstalled nondestructive soil‐solution sampler. Soil solutions were collected every 7 d with a syringe connected to the sampler. The results showed that pH of the soil solution was not the only factor controlling the concentration of Al. Significant positive linear correlations were found between Al and Ca as well as between Al and Mg in soil solutions from the controls. The ratio of base cations (BC, Ca+Mg) to Al might partly explain the high Al resistance of buckwheat. Oxalate secretion from roots significantly activated Al in acid soils, which may be important for changes of Al in soil solutions, but it also caused decreased concentrations of Ca, Mg, and Mn. It is concluded that the variation of metal concentrations including Al, Ca, Mg, and Mn is a holistic effect involving competition for exchange sites among Ca, Mg, H, and Al, the chelation by oxalate secreted from roots, and metal uptake by buckwheat.     

Long‐term effects of organic manure and manufactured fertilizer additions on soil quality and sustainable productivity of finger millet under a finger millet–groundnut cropping system in southern India

In a 20‐yr‐old long‐term experiment, the impact of continuous application of organic manures and inorganic fertilizers on soil quality and the sustainability of finger millet production was conducted on two cropping systems: finger millet and finger millet–groundnut on an Alfisol of semi‐arid southern India. The study was conducted from 1992 to 2011 at the All India Coordinated Research Project for Dryland Agriculture, UAS, Bangalore, using a randomized block design. The treatments comprised of T₁: control [no fertilizer and no farmyard manure (FYM) applied], T₂: FYM 10 t/ha, T₃: FYM 10 t/ha + 50% of recommended NPK (50:50:25 kg/ha), T₄: FYM 10 t/ha + 100% of recommended NPK and T₅: 100% recommended NPK. Comparison of long‐term yield data between treatments was used to calculate a ‘sustainability yield index’ (SYI), which was greatest for T₄ (FYM 10 t/ha + 100% of recommended NPK), in both rotational (0.68) and monocropping (0.63) situations. Soil quality indices were determined using principal component analysis linear scoring functions. The key indicators which contributed to the soil quality index (SQI) under rotation were organic C; potentially available N; extractable P, K and S; exchangeable Ca and Mg; dehydrogenase activity and microbial biomass C and N. The largest SQI (7.29) was observed in T₄ (FYM 10 t/ha + 100% NPK), and the smallest (3.70) SQI was for the control. Application of 10 t/ha FYM together with NPK (50:50:25 kg/ha) sustained a mean yield of 3884 kg/ha.