澳大利亚作物高产技术的进展


John S. Glendinning
Australia Pty Ltd 231 Miller Street North Sydney NSW 2070 Australia


　　原文摘要 ABSTRACT

　　尽管最高产量研究（MYR）这个术语在澳大利亚没有普遍使用，但最高产量研究的概念已在很多研究项目中广泛应用。

　　Although the term Maximum Yield Research is not commonly used in Australia, the concept of MYR is widely adopted in many research programmes.

　　土壤水分有效性是限制栽培作物面积及其产量的主要因素。应用能够改善单位有效水分生产力的措施对取得高产是非常关键的。这包括适度的养分（特别是氮和磷）、杂草控制、土壤结构改良、pH值及土壤盐渍化控制、种植密度、播种深度、操作时序以及其它因素。

　　Soil moisture availability is the major factor limiting the area sown to crops and their yield. Adoption of practices which improve output per unit of available moisture are critical to the achievement of high yields. These include proper nutrition, especially nitrogen and phosphorus, weed control, soil structure improvement, pH and soil salinity management, plant density, seeding depth, timeliness of operations and other factors.

　　有证据表明，小麦的产量潜力是每公顷每毫升水蒸腾量产20公斤小麦，而实际很少有产量能达到这个水平的一半。考察以往的研究结果，即使在试验的条件下，也很难达到根据土壤水分有效性所计算出来的产量潜力。

　　It has been shown that potential wheat yields are 20 kg of grain per ha per mm of water transpired, in situations where yields rarely reach half that level. Examination of past research results indicates that crop yields, even in research trials hardly ever reach their yield potential, as calculated from soil moisture availability.

　　本文将讨论上述一些作物生产方面的近期进展。

　　Recent developments in some of these aspects of crop production are discussed.

　　1.引言 INTRODUCTION

　　农业在澳大利亚的经济中占有十分重要的地位，农业又主要以放牧为基础，放牧通常全年进行，但也有很少量的牛以围栏饲养，以满足专门的市场需求。

　　Agriculture is of major importance to the economy of Australia and is based mainly around livestock grazing, usually for the full year except for very small numbers of cattle in feed lots to meet the demands of specialized markets.

　　约有17.4万农户从事农业，农场规模从1公顷到50万公顷以上不等。较大的农场因偏远且降雨量少而从事畜牧业，载畜能力也低，很多地方20公顷左右的面积仅载约一头牲畜。农业从业人员约为39万人，即约合澳大利亚总劳力的6%。

　　There are some 174 000 holdings devoted to agriculture, ranging in size from about 1 hectare to over 500,000 ha. The larger holdings are devoted to livestock and due to their remoteness and low rainfall, carrying capacity is also low, with many areas carrying only about a beast to 20 ha or so. Agriculture employs some 390,000 people or about 6% of the total workforce of Australia.

　　现在种植业具有十分重要的意义。尽管1900年仅有350万公顷左右的土地用于耕种，自1980年以来，这个数字一直稳定地增长，粗略地说，每年有1.8~2千万公顷的土地被用于种植业。澳大利亚最大的作物是小麦。每年小麦的播种面积约为1100万公顷，平均产量约1500公斤/公顷。（澳大利亚联邦，1991）。

　　 Cropping is now of major significance, although in 1900, only some 3.5 million hectares were cropped. This area has steadily increased and since 1980, approximately 18-20 million hectares have been under crop each year. By far the biggest crop in Australia is wheat. About 11 million hectares are sown annually and yields average about 1500 kg/ha. (Commonwealth of Australia. 1991)

　　目前每年大约有1800万公顷土地用于种植作物。这与近3亿公顷的天然或未改造牧场及2.8~3千万公顷的播种牧场的巨大面积形成了对比。

　　Currently, there are approximately 18 million hectares planted to crops annually. This compares to the vast areas, up to 300 million hectares, of native or unimproved pastures used for grazing livestock and the 28-30 million hectares of sown pastures.

　　 牧畜数量在过去10年来发生了变化，变化幅度大约是2~2.5千万头牛和1.3~l.6亿头羊，其它种类动物包括山羊、猪及家禽。

　　Livestock numbers in the past 10 years have fluctuated in the approximate range of 20-25 million head of cattle and 130-160 million head of sheep. Other classes of animals include goats, pigs and poultry.

　　 澳大利亚以气候多变闻名，至少从农业观点来看是这样。许多人认为土壤水分和降雨量是澳大利亚农业生产的主要限制因素。但是，很多情况下水的利用效率很低，这样，更好地利用现有的土壤水分给农牧业生产提供了增产潜力。

　　Australia is notable for its erratic climate, at least from the viewpoint of agriculture. Soil moisture and rainfall are regarded by many as the major limitations of agricultural production in the country. However, there are many situations where water-use efficiency is very low and the potential exists to increase crop and pasture production, thus making' better use of the soil moisture that is available.

　　 已根据如下一些情况建立了灌溉区：

　　Irrigation areas have been established, based on:

　　-大型能源和灌溉综合计划；

　　 large multi-purpose schemes for power generation and irrigation supply;

　　-河流水系的水流控制；

　　control of water flows in river systems;

　　-私人开发的抽水系统的地下水供给；

　　under-ground supplies with privately developed pumping systems and

　　-简单的集水系统以补充园艺开发用水。

　　simple water harvesting systems for use as supplementary water supplies for horticultural developments.

　　表1列有10种最重要的作物、其生产面积、过去3年它们的平均产量以及各自的产值（澳大利亚联邦，1991）。

　　Table 1 shows the 10 most important crops, their areas of production, their average yields of the last 3 years and their value of production (Comm. of Aust. 1991).

(表：表1 1988-89到1990-91澳大利亚种植的主要作物平均值 )

Crop 作物 Area sown 播种面积 Production 产量 Value 产值
000 ha 千公顷 000 tonnes 千吨 $US m 百万美元
Wheat 小麦 8945 13479 1900
Barley 大麦 2270 3568 375
Oats 燕麦 1300 1725 153
Maize 玉米 53 215 25
Sorghum 高粱 593 1274 145
Rice 水稻 103 778 89
Sugarcane 甘蔗 393 26306 502
Cotton 棉花 226 231 343
Vegetables 蔬菜 121 N. A.缺少数字 975
Fruit 水果 175 N. A.缺少数字 1314

　　小麦、羊毛、羊肉和牛肉的总产值约为农业总产值的一半。如表2所示，在过去25年多的时间里，农业出口值按不变货币计算翻了一番，但在占澳大利亚总出口的比例上减了半（Reid，1990）。这种减少部分地由于增加了制造业产品和矿物的出口。

　　The total value of wheat, wool, mutton and beef production is about half the total value of agricultural production. As shown in, during the last 25 years or so, the value of the agricultural exports, in constant money terms, has doubled but the proportion these exports form of the total Australian exports has halved (Reid 1990). This decline is due in part, to the rapid growth in the export of manufactured goods and minerals.

(表：表2 农产品出口及其对国民经济的贡献(Reid 1990) )

　 Index of volume of exports of rural origin 农产品出口数量指数 Rural exports as percentage of total exports 农产品出口占总出口的百分比
(1951-52 = 100) 1951~52年度为100 (constant dollars) 美元不变价
1961-62 168 78
1966-67 191 68
1971-72 244 50
1977-78 267 43
1981-82 262 41
1985-86 329 35

　　2.作物高产技术的发展 DEVELOPMENTS IN HIGH YIELD PRODUCTION

　　2.1.土壤与植株分析 SOIL AND PLANT ANALYSIS

　　澳大利亚肥料股份有限公司于1963年在新南威尔士州首先建立了第一个商业性土壤测试实验室。现在主要的商业性实验室分布在昆士兰、新南威尔士、维多利亚及西澳大利亚等州，由各大肥料公司经营。它们都使用标准分析方法。

　　The first commercial soil testing laboratory was established by the Australian Fertilizers Limited in NSW in 1963. Major commercial laboratories are now operated in Queensland, NSW, Victoria and Western Australia by the major fertilizer companies. Standard analytical methods are used in all cases.

　　另外，一些小实验室提供“独立”服务，各州农业署及联邦科学和工业研究组织（CSIRO）也开办试验室以支持其研究项目。

　　In addition, a number of small laboratories provide an “independent” service and the various state Departments of Agriculture and CSIRO operate laboratories to support their research programs.

　　还有一些植物快速测试工具箱投入使用，大部分是根据欧洲或美国的研究成果，其中有一种是根据联邦科学和工业研究组织的研究而制造的（Bouma和Dowling 1982，Bouma和Dowling 1984，Irving和Bouma1986）。

　　There are also a number of rapid plant testing kits in use, most of which are based on European or US research. One of these kits is based on CSIRO research (Bouma and Dowling 1982, Bouma and Dowling 1984, Irving and Bouma 1986).

　　2.2.小麦 WHEAT

　　澳大利亚的小麦生长在从亚热带到地中海类型的环境中，生长期间雨水的变化很大。北部的小麦栽培区，大部分小麦用水降于生长季之前，作物生长主要依靠休闲时土壤积蓄的水分。在南部小麦栽培区，大部分雨水分布在4至10月份之间，这是小麦大致的生育期，尽管也有一些地区土壤水分是靠休闲时储蓄的。如表3所示，澳大利亚小麦产量的历史变化趋势表明了农业措施对土壤肥力的影响。1870~1900年的减产是由于连作使土壤肥力迅速下降。休闲、开发更肥沃的地区及使用新品种又使产量增加。因此到1940年，又回到了1870年代的水平。然而，自那时起发展就不显著，虽然使用氮肥及改进栽培技术，平均产量没有超过1500公斤/公顷。部分原因是将小麦生产推广到降雨量较少的地区。

　　Wheat is grown in Australia in environments ranging from sub-tropical to Mediterranean. Growing season rainfall is highly variable. In the northern wheat growing areas, most of the water used by the wheat crop falls before the growing season and the crop is grown mainly on stored moisture from fallowing. In the southern areas, most of the rain falls in the April to October period, which approximates to the growing season, although in some southern areas moisture is also stored through fallowing. The historic trends in Australian wheat yields, as shown in Table 3, show the impact of farming practices on soil fertility. The decline in yields in the period from 1870 to 1900 was due to the rapid decline in fertility under continuous cropping. Fallowing, the development of more fertile areas and new varieties lifted yields again, so that by 1940, they were back to the levels of the 1870 period. However, despite the use of nitrogen fertilizer and other improved practices, little progress has been made since that time and average yields have not advanced beyond 1500 kg/ha. This is due in part to the extension of wheat production into areas which receive only limited amounts of rainfall.

(表：表3 澳大利亚小麦产量趋势(Williams 1991;Cimm of Aust.1991) )

Ten year period ending 十年期结尾 Ten year mean yield to 1980 十年平均产量截止1980年 Annual Yield from 1985 to 1990 年产量1985-1990年
kg/ha/yr 公斤/公顷/年
1870 860
1900 490
1950 860
1980 1275
1985 1560
1986 1370
1987 1480
1988 1020
1989 1010
1990 1580

　　在提高作物生产技术的努力中，各州农业署和大学所进行的小麦育种项目是引人注目的，自从引入植物品种权，伴随着玉米、高梁和向日葵育种项目，私人种子供应商开始进入杂交小麦育种领域，一些杂交小麦被大规模种植。

　　Notable amongst the efforts to improve crop production techniques are the wheat breeding programmes conducted by the various state departments of agriculture and universities. Since the introduction of Plant Variety Rights, private seed suppliers have entered the field of hybrid wheat breeding as an adjunct to their maize, sorghum and sunflower breeding programmes, and a number of hybrid wheats are grown commercially.

　　小麦育种项目的一个重要部分是抗病育种，特别是针对各种叶和茎病，致病菌系经常改变，致使小麦的遗传抗性不断地失效。

　　A major component of wheat breeding programmes is to incorporate disease resistance, particularly to the various leaf and stem diseases, the races of which frequently change and genetic resistance continually breaks down.

　　与育种项目密切联系的是进行相关技术的调查，如播期和播种量。目前大部分育种项目的品种选择着眼点是基于高土壤肥力水平，对作物营养的调查很大程度上由肥料商来完成，尽管过去全国和州的土壤肥力和作物营养项目是由联邦科学和工业研究组织和州农业署进行的。

　　Allied to the breeding programmes are investigations into other associated techniques such as time of planting and seeding rate. Even though most variety selection aspects of breeding programmes are made under high soil fertility levels, investigations into the nutrition of the crop in recent times, are largely left in the hands of the fertilizer producers, although national and state soil fertility and crop nutrition programmes were conducted by CSIRO and the state departments of agriculture in the past.

　　由于澳大利亚降雨类型多变，人们常认为土壤水分给作物产量定了上限。但以French和Schultz（1984）的工作为例，表明在南澳大利亚小麦产量的潜力是每公顷每毫米水分20公斤，而相比该地区的实际产量还不到此一半（French 1990）。在肥料试验小区里尽管产量在试验中从0.8增至1.8吨/公顷（French和Schultz，1984），但试验似乎不太好，因为根据降雨和有效水分数据计算值，距可达到的产量潜力还存在4吨/公顷的差距。

　　Because of the erratic rainfall patterns in Australia, it is often considered that soil moisture sets the upper limit on crop yield potential. However, the work of French and Schultz (1984) has shown, for example, that the potential wheat yield in South Australia is 20 kg grain per hectare per mm of moisture used compared with actual district yields of less than half the potential (French 1990). In fertilizer research plots, even though yields were increased from 0.8 to 1.8 tonnes per ha in one experiment (French and Schultz 1984), the research was seen as being inadequate because there was still a deficit of over 4 t/ha below the potential yield as calculated from data on rainfall and available moisture.

　　作物播期依赖水分供应产生重要效应，这可能是非常关键的。

　　An important effect of the dependence on water supply is that the time of planting the crop can be critical.

　　调查1958~68年期间在南澳大利亚所得到的研究数据（French和Schultz，1984）说明最佳播种期后每推迟一周播种，小麦的产量就减少200~250公斤/公顷，如表4所示。

　　Examination of research data obtained over the period 1958-68 in South Australia (French and Schultz 1984), showed that for each week's delay in planting after the optimum date, the yield of wheat grain of the varieties sown at the time, was reduced by 200-250 kg/ha, as shown in Table 4

(表：表4 1958-68年澳大利亚南部播种时间对小麦产量的影响(French and Schultz 1984) )

District. 地区 Ave.Rainfall Apr.-Oct. 4-10月平均降雨量(mm)毫米 Optimum time of sowing 最佳播种时间 Rate of decline of grain yield for each week's delay in sowing 每推迟一周播种籽粒减产率
Eyre Peninsula 艾尔半岛 220 10-20 May 5月10-20日 5% (90 kg/ha/wk) until mid-June and then 12% (250 kg/ha/wk) 6月中旬前减产5% (90 kg/ha/周)，以后减产12% (250 kg/ha/周)
York Peninsula 约克半岛 400 10-25 June 6月10-25日 5% (200 kg/ha/wk)
Mid-North 中北部地区 380 1-5 June 6月1-5日 8% (200 kg/ha/wk)

　　在南澳大利亚试验田里，French和Schultz鉴定了作物产量的主要限制因素，证明当采取措施克服氮不足，杂草和根部病害后，小麦产量从2.2吨/公顷增加到3.9吨/公顷。由潜在产量的54%提高到潜在产量的95%。

　　French and Schultz (1984) identified the major limiting factors to crop yield and showed that when steps were taken to overcome nitrogen deficiency, weeds and root disease in research plots in South Australia, wheat yields were increased from 2.2 t/ha to 3.9 t/ha, an increase from 54% of the potential yield to 95% of potential yield.

　　然而他们的工作表明，在南澳大利亚约65%的小麦产量波动与4月到10月的降雨量变化相联系。6月至8月的冬季月份比其他时间的降雨对高产影响更大。但其他地区有不同的影响，因为降雨量在不同季节可能差别3到4倍，不同年份的产量潜势差异也可能很大，尽管其他因素也可能造成这一差异。

　　However, their work showed that in South Australia, about 65% of the variation in wheat yield is associated with the variability of rainfall in the April to October period. Rainfall in the winter months of June to August, is more effective in producing high yields than is rain at other times. A different effect occurs in other areas however, since rainfall may vary by three to four fold between seasons. The variation in potential yield from year to year may also be very large although other factors can contribute to this variation.

　　在新南威尔士州南部的小麦产区，Angus和Fischer （1991）正在研究小麦最高产量的最佳肥料需求。一个重要的发现是最有效的施氮时期是播种时或播种前。这得到Cooper （1974）在昆士兰州南部工作的支持，那是在夏季雨养地区，作物几乎完全靠贮蓄的水分；而且Strong（1986）在相同地区的灌溉麦田里的工作也证实了其发现。Strong的工作表明，分期施用氮并不比播种前一次施用增产更大，但分期施肥总是提高蛋白质水平。这似乎是灌溉田小麦分施氮肥比播种前一次施用所具有的优点。

　　In the wheat areas of southern NSW, Angus and Fischer (1991) are investigating the optimum fertilizer requirements for maximum wheat yields. A major finding is that the most efficient use of nitrogen application appears to be when it is applied at or before sowing. This is supported by Cooper (1974) in his work in southern Queensland in a summer rainfall area where the crop is grown almost entirely on stored moisture, and by Strong (1986) in his work on irrigated wheat in the same area. Strong's work showed that the splitting application of N gave no consistent increase in yield over applying it all before planting, however, splitting the application invariably gave an increased protein level. This seems to be its main advantage for irrigated wheat over applying all the N before planting.

　　然而，Angus和Fischer的工作指出，在小麦带南部的栽培实践中，应有可能推迟所需大部分氮肥的施用时间，直到土壤水分可能更有效的时候，以避免任何减产。这种方法的优点是农民可以推迟他们在化肥上的投资，直到确认更能得到回报的时候。

　　However, Angus and Fischer's work suggests that, in practice in the southern wheatbelt, it should be possible to delay the application of a major amount of the nitrogen requirement until a better indication of the likely soil moisture level is available, without suffering any yield reduction. This approach has the advantage that growers can defer their investment in fertilizer until there is more certainty of getting a return on it.

　　Angus、Van Herwaarden和Howe（1991）也研究了氮肥、轮作及在有小麦全蚀病真菌（Gaeumannomyces graminis Var.tritici）限制小麦产量的地方引进油料填闲作物的效果。部分结果如表5所示。

　　Angus, van Herwaarden and Howe (1991) have also investigated the effects of nitrogen fertilizer, rotations and the introduction of oil-seed break crops where the Take-all fungus (Gaeumannonyces grwdnis, var. tritici) has restricted wheat yields. Some of their results are shown in Table 5.

(表：表5 前茬作物和施氮肥对小麦产量和籽粒蛋白质含量的影响(Angus et al 1991) )

Previous crop 前茬作物 Wheat yield小麦产量 Grain protein 籽粒蛋白质含量
kg/ha 公斤/公顷 % yield产量 (kg/ha)公斤/公顷
Canola 油菜 3580 11.2 400
Linseed 亚麻籽 3400 10.5 357
Indian mustard 芥菜 3770 10.8 407
Oats 燕麦 3310 9.6 318
Wheat 小麦 3230 10.4 336
(lsd P=0.05) 180 0.3 　

　　1987年在维多利亚州182个农场的一项调查中，Clark（未发表）发现，在羽扇豆、油菜籽和三叶草后种植小麦的平均产量最高，表6说明这些轮作方式还可以得到最高的毛边际收益，比接小麦或燕麦茬约高50%。

　　In a survey of 182 farms in 1987 in Victoria, Clark (unpublished) found that highest average wheat yields were obtained following lupines, canola and clover. As shown in Table 6, these rotations also led to the highest gross margins, which were about 50% higher than those obtained following wheat and oats.

(表：表6 1987年前茬作物对作物产量的影响(Clark unpublished) )

Previous Crop 前茬作物 No. of sites点数 Yield产量kg/ha公斤/公顷 Gross Margin毛利$US/ha美元/公顷
Lupines 羽扇豆 40 3200 161
Clover 三叶草 16 3100 159
Canola 油菜 17 3200 149
Peas 豌豆 9 2500 122
Pasture 牧草 24 2600 115
Oats 燕麦 8 2400 113
Wheat 小麦 41 2500 101
Fallow 休闲 26 2200 98

　　Clark（未发表）的其他观察说明了植株密度在产量中的重要性。当品种 Oxley以110公斤种子/公顷播种，（播种深度增加到42.5毫米时），其密度达到最高值210株/平方米。当播种深度为65毫米时，植株密度相应下降到150株/平方米。其它品种也有相似的趋势。

　　Other observations by Clark (unpublished) showed the importance of plant population in yield production. When the variety Oxley was sown at 110kg seed/ha, plant population rose to a maximum of 210 plants/sq.m., when planting depth was increased to 42.5 mm. Plant population subsequently declined to less than 150 plants per sq. m. at about 65 mm planting depth. Other varieties showed similar trends.

　　Angus和Fischer（1991）还研究了小麦的氮肥施用时间，结果表明，在四年中氮肥的最高农学效益是：当雨水较平的年份里，每施1公斤氮，产19、23和25公斤小麦；较干旱年份则每公斤氮生产4公斤小麦，当氮肥在Zadok定义的生长期30时施用，在多雨年份，则氮肥的农学效益为每施1公斤氮22公斤小麦，而在干旱年份里农学效益则为零。

　　Angus and Fischer (1991) have also investigated the timing of nitrogen application to wheat. Their results showed that in a 4-year period the maximum agronomic efficiencies from nitrogen fertilizer were 19, 23 and 25 kg grain for each kg of applied N in the years of about average rainfall and 4 kg grain for each kg of applied N in the drought year during that period. For nitrogen applied at about Zadok's growth stage 30, the agronomic efficiency of the nitrogen fertilizer was 22 kg grain for each kg of applied N in the wet years and nil in the drought year.

　　Angus将于1992年开始一个新项目，以研究植物营养另外一些问题，包括使用氯化钾控制病害。这个项目的重点之一是研究北美使用氯化钾控制根腐病（此处指全蚀病）的结果能否在澳大利亚的条件下重复，此外还研究钾在小麦营养中的作用，目前尚无结果。

　　A new research project to be commenced by Angus in 1992 will investigate other aspects of plant nutrition, including the use of muriate of potash in disease control. This project will, amongst other aspects, investigate whether results obtained in North America from the use of KCl in the control of root rot diseases, in this case take-all, will be obtained in Australian conditions, as well as investigate the role of potash in wheat nutrition. No results are available at this stage.

　　事实上世界上任何地方发展作物生产技术都包含相同的内容，即：利用土壤和植株测试服务预报氮磷需求，土壤结构改良的要求、pH及盐渍化程度、全蚀病的感染程度、作物出苗后追施氮肥的需要，等等；监控作物出苗后的发育情况已为更多的先进农民所采用；计算机辅助服务也用来帮助这些生产措施。

　　In practice, developments of crop technology include the same sort of practices adopted elsewhere in the world, namely: to utilize soil and plant testing services to predict N and P requirements, the need for soil amendments to improve soil structure, pH and salinity levels, infestation levels of take-all, the need for additional N after crop emergence, and so on; monitoring the crop's development after emergence, which is practised amongst the more advanced growers; and computer assisted services are used to help with these practices.

　　Clark（未公开发表）和Hutchings（未公开发表）已在维多利亚和新南威尔士州南部鉴定了影响作物产量的主要因素。他们分析了客户的作物生产记录并能够分析出对作物产量起主要作用的措施和因素。

　　Clark (unpublished) and Hutchings (unpublished) have identified the major factors influencing crop yields in Victoria and southern NSW. They have analyzed crop production records of their clients and have been able to identify those practices and factors which make the major contribution to crop yield.

　　他们的研究结果和French（1990）的大概一致，表明达到高产高效的重要因素是：

　　Their findings are broadly in agreement with those of French (1990) and show that the most important factors in achieving profitable crop yields and production are:

　　-适时作业，特别是播期；

　　Timeliness of operations, particularly time of planting.

　　-病虫害防治；

　　 Pest and disease control.

　　-植株密度；

　　Plant population.

　-土壤肥力和施肥；

　　Soil fertility and fertilizer use.

　　-土壤结构；

　　 Soil structure.

　　-最适合当地条件和播期的作物品种；

　　 Crop variety best suited to the time of planting and district.

　　-杂草控制及适时处理，以防止其蔓延危害作物。

　　Weed control and timing of treatment to avoid weed penalty.

　　2.3.玉米 MAIZE

　　如果在新南威尔士州南部发展圈养牛计划实现的话，澳大利亚的玉米面积有可能有较大的发展。主要是开发高质量的青贮或者刈割饲料，可能会有更多的开发合同。

　　The area of maize grown in Australia has the potential to expand quite significantly if plans to develop cattle feed-lots in the southern parts of NSW come to function. A major requirement for these developments will be the supply of high quality maize silage or green-chop, which are likely to be grown under contract.

　　植物育种计划已经培育出不少当地的高产杂交玉米，而且还有从北美进口的杂交玉米，它们很适应澳大利亚的条件。

　　Plant breeding programmes have developed many high-yielding local maize hybrids; as well, hybrids imported from North America are available and are reasonably well adapted to Australian conditions.

　　玉米的播种面积以及它在澳大利亚农业中的重要性似乎还不能保证人们投入很大的研究力量，特别是再看到美国对此已经做了相当多的工作，而且相当部分的研究结果可以直接应用于澳大利亚。

　　The area sown to maize and its relative importance in Australian agriculture do not seem to warrant a significant effort being made with this crop, particularly in view of the vast amount of research conducted on it in the USA. Much of that research is directly applicable in Australia.

　　2.4.粒用高梁 GRAIN SORGHUM

　　高粱生产区分布于新南威尔士和昆士兰两州以前肥沃的土壤。在这种土壤里已经种植多年高粱了，依靠天然和豆科植物残存于土壤中的氮养分。

　　The main production of grain sorghum is in areas of NSW and Queensland on what were originally highly fertile soils. The crop has been grown for many years on these soils on the residual nitrogen present in the soil from the native, leguminous vegetation.

　　1989~1991年，Incitec Ltd公司（Good 1991）在新南威尔士州的利物浦平原地区进行了田间试验，结果表明现在高粱对施肥（特别是氮肥）有显著反应，而以前并非如此。

　　Field trials conducted by Incitec Ltd. (Good 1991) in the Liverpool Plains area of NSW in the 1989-1991 period have shown that grain sorghum now responds significantly to applications of fertilizer, particularly nitrogen, in situations where it did not do so previously.

　　对此有一些可能的解释，但较好的解释是，因为养分被移走，使用了良种和先进的农作技术，包括更有效的保水、除草、作物轮作和适时播种，此外还有良好的害虫防治技术。

　　There are a number of possible explanations for this, but the most likely ones are removal of nutrients, improved varieties, improved farming techniques, including better moisture conservation, weed control, crop rotations and timely planting date; and improved pest control practices.

　　不过，土壤水分影响和前作效应对高粱生产是明显的，这与其它作物相同。表7总结了Incitec Ltd公司在新南威尔士州进行了三年的高梁试验项目。

　　Nevertheless, the influence of soil moisture and the effect of the previous cropping history are apparent with the-production of this crop as with the other crops. This is illustrated in Table 7, which summarizes the results of the grain sorghum trial program carried out by Incitec Ltd., over a three year period in NSW.

(表：表7 1989~1991年利物浦平原进行的7个高粱试验平均产量和不同耕种措施的效果(Good 1991) )

　 Rate of Nitrogen fertilizer施氮量 (kg N/ha)公斤N/公顷
0 20 40 80 160
Trial 1: Yield kg/ha 10 months fallow after wheat 试验1：小麦后休闲10个月 产量（公斤/公顷） 2500 3700 4650 5900 7000
Trial 2: Yield kg/ha No-till after wheat 试验2：小麦后免耕产量 （公斤/公顷） 1360 2150 3350 4000 5050
Average yield of 7 trials - kg/ha 七个试验平均产量 （公斤/公顷） 4120 4890 5500 6060 6650

　　产量之间差异较大是由于各自不同的农艺措施，这包括作物轮作、休闲时间长短及它们对土壤水分的影响。

　　The wide range in yields is due to the particular farming practices which include crop rotation and length of fallow and their effect on soil moisture levels.

　　2.5.水稻 RICE

　　澳大利亚水稻主产区为新南威尔士州南部及昆士兰州北部，面积约各有10万公顷和3千公顷（Reid 1990）。现在每年总产75到80万吨，平均产量约 6.75~7.00吨/公顷（澳大利亚联邦，1991）这属世界最高产的稻区之一。澳大利亚大约90%的稻米用于出口。

　　The main regions of rice production in Australia are southern NSW where there is about 100,000 ha, and north Queensland where there is about 3,000 ha (Reid 1990). The production is now 750,000 to 800,000 tonnes annually with average yields of about 6.75 to 7.00 tonnes per ha. (Comm. of Aust. 1991). These are amongst the highest of any rice growing region of the world. Approximately 90% of the rice grown in Australia is exported.

　　使水稻单产提高的主要措施是病虫害和杂草防治、适时播种和施肥。最主要的肥料是氮肥，施用量达200公斤/公顷，大部分是分期施用。新南威尔士州南部（Angus，Bacon和Reinke 1992）的大田措施是在水稻的持续灌水期施用大部分其所需氮肥，其余部分在穗分化始期施。

　　The main practices which lead to these high average yields are pest and weed control, time of planting and fertilizer use. By far the main fertilizer used on rice is nitrogen, which is applied at rates up to 200 kg/ha of N, mostly as a split application. Commercial practice in rice production in southern NSW (Angus, Bacon and Reinke. 1992) is to apply the major portion of the crop's nitrogen requirement at permanent flood and the remainder at panicle initiation.

　　这些方法主要是根据Bacon和Heenan （1984）及Bacon（1985）的研究而来的。最近， Bacon等（1987a）和Batten等（1991）开发了简单的茎叶密度和氮含量的植株测试方法。这些测试方法使人们能够更好地管理作物的氮素需求，以避免过量施用氮肥带来的稻穗不育及减产。

　　These practices have developed mainly from research by Bacon and Heenan (1984) and Bacon (1985). More recently, Bacon et al (1987a) and Batten et al (1991) have developed simple plant tests for shoot density and nitrogen content. These tests enable the better management of the crop's nitrogen requirement to prevent head sterility and loss of production when excessive amounts of nitrogen fertilizer are applied.

　　Bacon等（1987b）的研究表明，半矮化型水稻品种在持续灌水期施氮肥的产量反应比在穗分化始期施的反应更大。

　　Studies by Bacon et al (1987b) have shown that with semi-dwarf varieties of rice grown for high yield production the response to N applied at permanent flood far exceeds that of N applied at panicle initiation.

　　2.6.其他作物 OTHER CROPS

　　除了相当活跃的植物育种项目中有向日葵育种课题外，对向日葵和油菜等大部分其它大田作物的特定需求方面很少有正式的研究。

　　Very little formal research has been carried out into the particular requirements of most of the other field crops, such as sunflowers and canola, except for quite vigorous plant-breeding programmes in the case of sunflower.

　　在昆士兰州和新南威尔士州北部地区可能有肥效反应的土壤上，由Incitel Ltd公司（Good 1991）进行了少量部分这些作物简单的肥料试验研究，结果见表7。

　　There has been a limited amount of research in some of these crops, in the form of simple fertilizer trials, carried out by Incitec Ltd (Good 1991) in Queensland and northern NSW on soils similar to those where the fertilizer responses shown in Table 7 were obtained.

　　一个典型的向日葵肥料反应如表8所示。

　　A typical response to fertilizer on sunflower is shown in Table 8

(表：表8 1990-91年新南威尔士州利物浦平原向日葵的氮肥肥效(Good 1991) )

Nitrogen Rate 施氮量 Yield 产量 Oil content 含油量 Seed Value 种子价值 Value of yield 产值
kg N/ha 公斤N/公顷 kg/ha 公斤/公顷 % $US/t 美元/吨 $US/ha 美元/公顷
0 1879 40.0 188.00 353.25
20 2131 39.7 187.00 398.5
40 2320 39.5 186.50 432.68
80 2456 39.2 185.70 456.08
160 2528 38.1 182.70 461.86

　　尽管随着氮肥施用量的增加含油率下降，但每公顷最高油产量仍得自于最高的施氮肥处理。然而回归分析表明最佳收益的氮肥处理是50公斤N/公顷。

　　Despite the reduced oil content with increasing nitrogen rates, the highest oil production per hectare came from the highest nitrogen treatment. However, regression analysis shows that the most profitable nitrogen treatment is 50 kg/ha of N.

　　在油菜方面，与加拿大的经验相似，田间观察指出需要高水平的硫，至少在新南威尔士州南部和维多利亚州是这样。当前推荐（Jordan私人通讯）油菜籽施用20~30公斤/公顷的硫，具体要看以前的施肥和耕作历史情况。

　　In the case of canola, as with Canadian experience, observations in the field indicate that it requires high rates of sulphur, at least in southern NSW and Victoria. Currently it is recommended (Jordan personal communication) that 20 to 30 kg/ha of sulphur be applied to canola, depending on the previous fertilizer and cropping history.

　　French（1990）用其与小麦相似的研究方法，根据土壤有效水分评估了豆科粮食作物、羽扇豆和紫花豌豆的产量潜力。在考虑到直接蒸发损失后，产量潜力为每毫米蒸腾水15公斤/公顷。

　　In the case of grain legumes, lupines and field peas, French (1990) has assessed their potential yields, based on available soil moisture similarly to his work with wheat. After allowing for the loss of water by direct evaporation, the yield potential has been shown to be 15 kg of grain per hectare per mm of water transpired.

　　3.饲料作物 FORAGE CROPS

　　Crofts（1963）在悉尼地区调查了集水及其对奶牛生产的效应。接着，这种在相对较温和的海洋性气候环境下进行的研究原理又被用于高原地区，那里海拔1000米或更高，冬季的低温限制牧场和饲料作物的生长。

　　Crofts (1963), examined water-harvesting and its effects on dairy production in the Sydney area. Subsequently, the principles established in that work which was conducted in the relatively mild coastal climate, were taken into the tableland areas, where at altitudes of about 1000 m or more, low temperatures in the winter limit pasture and forage crop growth.

　　这些原理针对高原地区的牛、羊生产进行了调整（Crofts 1996），显然，在该环境条件下影响冬季燕麦生产的三个最重要的因素是：播种量、施氮肥量及播种期。

　　Those principles have been adapted for sheep and beef production in tableland areas (Crofts 1966) where it is clear that the three most important factors influencing winter feed supply from oats in that environment are seeding rate, nitrogen supply and time of seeding.

　　4.牧场 PASTURES

　　讨论澳大利亚的农业而不谈到牧场是不能算完整的，尽管这次会议的主要论题是作物生产。

　　No discussion of Australian agriculture is complete without some reference to pastures, even though this symposium is primarily concerned with crop production.

　　有关牧业生产的多方面已有大量的研究。这里只说澳大利亚牧业生产在多方面已经取得了很大的进展就足够了。一些重要的进展如下：

　　There has been a great deal of research into many aspects of pasture productivity but it is sufficient to say here that great advances have been made in a number of aspects of pasture production in Australia. Some of the important developments are:

　　牧场发展项目发现钼在酸性土壤上促进豆料植物的生长（Anderson 1940）

　　discovery that molybdenum is beneficial to legume growth in pasture development programmes in acid soils (Anderson 1940).

　　隐花狼尾草（Pennisetum clandestinum）牧草施肥量达到300公斤N /公顷时提高乳脂产量400%（Anon 1966）

　　application of up to 300 kg/ha of N to kikuyu (Pennisetum clandestinum) pastures increased butter-fat production by about 400% (Anon 1966).

　　在新南威尔士州的北部高原的禾本科?豆科牧草牧场上施用375公斤/公顷的过磷酸钙可增加梯牧草（牧场中禾本科牧草成分）的产量，并使放牧牛的生物量达常规只施用125公斤/公顷过磷酸钙的牧场2倍以上。牧草增产在很大程度上因为所施过磷酸钙中的磷和S。此外，由于增加了牧场中禾本科牧草的组成，牲畜的气胀病的发病率已明显降低(Wolfe 1974)。

　　application of 375 kg/ha single superphosphate to a grass-legume pasture on the Northern Tablelands of NSW, increased the DM production, the grass component of the pasture and more than doubled the liveweight gains of cattle grazing those pastures compared with the conventional application of 125 kg/ha SSP. While the increased production of pasture was due in large part to the P and S applied in superphosphate. a much lower incidence of bloat as a result of the higher grass component in the pasture was also apparent （Wolfe 1974）.

　　位于地中海类型环境的南澳大利亚牧场的载畜的潜力是，当年降雨量超过250毫米后，每25毫米为1.3头干绵羊等价值（French 1990）。

　　potential stock carrying capacity of pastures in South Australia in a Mediterranean environment, is 1.3 dse (dry sheep equivalents) for each 25 mm of rainfall above 250 mm annual rainfall (French 1990).

　　在雨季生长的热带禾本科草场施氮肥300公斤N /公顷，并配以冬季饲料作物及少量的粮食，可使每头奶牛产奶量增加1800升，或说每公斤氮增加12升奶。增施氮肥可进一步提高产奶量，并且使每公顷奶牛载畜4.9头（Cowan等 1991）。

　　application of 300 kg/ha of N to raingrown tropical grass pastures, integrated with winter forage crops and small amounts of grain supplements, led to an increase in milk production of 1800 litres per cow, or 12 L of milk per kg N. Further increases were obtained with higher rates of nitrogen fertilizer and stocking rates of 4.9 cows per ha. (Cowan et al. 1991).

　　在西澳大利亚使用钾把提高了以豆科牧草为主草场的生产能力，防止了豆科牧草在牧草比例中下降并扭转了盐渍化侵害。

　　application of potash fertilizer in Western Australia has improved the productivity of legume based pastures, prevented the run-down of the legume component of the pasture and reversed the onset of salinisation (Leach unpublished).

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