甲黄隆钠盐麦田除草试验

田间小区试验表明，甲黄隆钠盐对以播娘蒿、夏至草、荠菜为主的麦田杂草有优异防效，但需严格掌握使用时间，使用剂量及使用技术，在小麦３叶期以７．５克有效成分．公顷的剂量施用，甲黄隆钠盐对麦田杂草防效理想，且对小麦及后茬作物安全。     

3%世玛乳油防除麦田雀麦等杂草试验

结果表明，除草剂世玛不仅对麦田恶性杂草雀麦有良好的防效，而且对麦田常见的阔叶杂草如荠菜，播娘蒿，小花糖芥等也有很好的防效。3％世玛乳油20，25，30mg/667m^2药后40d，对雀麦防效依次为81.8%,87.3%,92.5%，对阔叶杂草防效依次为93．5％，95．7％，98．7％。适宜的用药剂量为25－30ml/667m^2。     

农药使用技术 小麦田除草剂混用技术

我国麦田主要杂草有野燕麦、看麦娘、硬草、播娘蒿、荠菜、猪殃殃、繁缕等,一般以阔叶类杂草为主.在麦田杂草防除过程中,特别是在小麦生长期内防除麦田杂草,为有效防除禾本科杂草和阔叶杂草,多采用除草剂混用的施药方法.下面简要介绍一些小麦田除草剂混用技术.     

甲磺隆防除稻茬麦田杂草的研究与应用

本文报道了１９９０－１９９５年甲磺隆防除稻茬麦田杂草的试验研究和推广应用结果。试验表明在小麦播后苗前和三叶一心期，６６７平方米用甲磺隆２．５－１０克，对多种杂草均有明显防效，其最适用量为５－７．５克／６６７米＾２。     

稻麦连作麦田化学除草

随着稻麦连作年限的增加,麦田草相发生了显著的变化,由麦豆,麦棉,麦饲等旱作连作麦田的繁缕,婆婆纳,播娘蒿,荠菜,芥菜,早熟禾等杂草为主,转变为以稻麦连作麦田的看麦娘,硬草,棒头草,猪殃殃,大巢菜等杂草为主,因此,生产上必须针对稻麦连作麦田的杂草群落特点,经过试验,示范,筛选出适宜的药剂品种和施药方法,达到安全,高效,经济,方便的目的。     

麦田杂草化学防除技术

小麦是重要的粮食作物,近几年来麦田杂草的发生日趋严重,明显地影响着小麦的丰产与丰收。据调查,河南省麦田杂草发生的主要种类有荠菜、播娘蒿、米瓦罐、猪殃殃、繁缕、牛繁缕、婆婆纳、刺儿菜、野燕麦、看麦娘、硬草等。在黄淮冬麦区麦田杂草在田间萌芽出土的高峰期一...     

稻茬麦田播前草害防除技术

我省农田化学除草中,麦田化除一直占有很大比例。近几年,麦田实行免耕,既省工又高产,正迅速被广大农户采用。1985年冬,我们分别在临安县西墅村陈朝荣户和余杭县长乐村陈文贤户的稻茬麦田,利用草甘膦和百草枯具有灭生性和遇土易纯化的原理,进行了对播前早期草害的防除试验,并取得了良好效果。临安等地今冬已打算较大面积应用推广。现将试验情况整理如下。材料与方法陈朝荣户和陈文贤户麦田的试验处理及材料分别如表1、表2所述。陈朝荣户麦田前作     

山西省麦蜘蛛及麦田杂草发生趋势预报

根据当前麦田红蜘蛛、杂草发生情况和小麦苗情长势,结合省气象台春季天气预报及历年发生资料综合分析,预计今春麦蜘蛛总体中等发生,南部旱垣、向阳坡地及部分扩浇麦田偏重发生,发生面积450万亩,发生高峰期较常年推迟5—7天,防治适期在3月下旬至4月上旬;麦田杂草偏重发生,发生面积650万亩,大部分麦田以播娘蒿、婆婆纳、荠菜、离子草、麦家公、     

麦草畏防除麦田杂草试验

沿淮地区的耕作制度大多为一麦一豆连作。小麦播种方式为撒播,难以进行人工中耕除草,因而草害严重,常造成草荒。麦田主要杂草为猪殃殃,其次为荠菜、播娘嵩、大巢菜、田旋花等。为寻找经济有效的除草剂和选用适宜浓度,1986年春进行了麦草畏麦田化学除草试验和示范,取得了理想的效果,现总结报告如下。一、材料和方法     

麦田除草剂──麦宝

麦田除草剂──麦宝麦宝是复配型麦田超高效茎叶兼土壤处理除草剂（以茎叶处理为主）。用于麦田（小麦、大麦、燕麦等）防除多种一年生和多年生杂草如：藜、猪殃殃、田蓟、反枝苋、蓼、地肤、麦家公、播娘蒿、田芥、麦瓶草、繁缕、母菊属、绿叶泽兰、宝盖草等。该药用药量...     

Influence of agronomic management of legume crops on soil accumulation with nitrate

Nitrate is known to accumulate under legume crops. The effects of legume crop, inoculation, row width, sowing rate, sowing date, and intra-cropping with wheat, on the amount and soil distribution of mineral N, residual soil water, crop biomass and crop N were studied at Wagga Wagga in south-east Australia. After removal of most of the above-ground plant material, the treatment effects on the biomass, N content, grain yield and grain N of wheat, established in the following season, were also measured. In a later experiment at Wagga, the recovery of 15N applied to the mid-row of lupin crops established at three row widths was estimated at crop maturity. At Condobolin, row width effects on the soil distribution of mineral N, biomass, N accumulation and N fixation of crop legumes and cereals, were determined. At physiological maturity, at Wagga Wagga, very little nitrate was left beneath cereals. Significantly more was left under legume crops, mostly below 30 cm of soil depth, and it was distributed differently depending on crop, inoculation, and sampling location. More nitrate was left under pea and faba than under lupin, and in response to inoculation. Mixing wheat with narrow-leaf lupin did not prevent nitrate accumulation in soil. For most of the legumes more nitrate was left in the mid-row than in the in-row; and more nitrate was left at the mid-row of lupin crops sown with wider rows. The additional nitrate left with wider rows increased the growth, N content, grain yield and protein of wheat established in the following season. 15N labelled nitrate applied mid-row was used less effectively by lupin as row width increased, in a dry season. At Condobolin, lupin established with wide rows used less soil nitrate than with narrower rows but maintained crop N by increased N fixation. In contrast, field pea maintained N demand by increasing nitrate uptake at intermediate row spacing. The study shows that the amount of nitrate accumulated in soil during legume cropping is susceptible to agronomic management, particularly crop selection, row width and inoculation; and that variation in the amount of this nitrate may carry forward to impact wheat production in the follow-on season.     

75%磺酰磺隆WG防除春小麦田杂草及安全性研究

为明确75%磺酰磺隆WG对春小麦田杂草的防除效果及对当季春小麦和后茬作物的安全性影响,采用茎叶喷雾处理进行了田间药效试验。结果表明:施药后45 d,75%磺酰磺隆WG 10~40 g/hm2对北方春小麦田稗草、狗尾草、藜和卷茎蓼株防效和鲜重防效均在84.8%以上,且对春小麦安全。75%磺酰磺隆WG对当季后茬敏感作物白菜、油菜、生菜的根长、株鲜重有不同程度的抑制作用。75%磺酰磺隆WG在春小麦田喷雾使用可以有效防除禾本科杂草和阔叶杂草,但当季后茬不能种植敏感作物白菜、油菜、生菜。     

Efficiency of HCl- and H2SO4-acidulated rock phosphates for a rice based cropping system

Pot experiments were conducted with an acid laterite soil and a shallow black calcareous soil to study the effect of initial application of North Carolina and Udaipur rock phosphates, acidulated with HCl or H₂SO₄ to the extent of 25, 50, 75 or 100% of the requirement for complete conversion into superphosphate, on the grain yield and P uptake by crops in rice—wheat and wheat—rice cropping sequences. The products obtained on acidulation with HCl or H₂SO₄ at a given degree behaved similarly. Rock phosphates partially acidulated with HCl or H₂SO₄ to 50–75% could be used successfully for growing rice or wheat on both the soil types. In the rice—wheat sequence, the wheat crop following rice gave very low grain yields compared to the wheat crop in the wheat—rice rotation, while in the wheat—rice rotation the rice crop following wheat gave yields comparable to that of rice in the rice—wheat rotation. The reasons for this differential effect have been made plausible. The studies indicate that a 50–75% H₂SO₄ - or HCl-acidulated rock phosphate may be used as a single application to an upland crop in an upland crop—rice rotation especially on acid soils, where the water soluble fractions of the product are used by the wheat crop. During the process of growth of the upland crop under aerobic soil conditions, the citrate soluble and insoluble fractions undergo such transformations that make it possible for the following rice crop to utilize them under waterlogged conditions.     

Pea–barley intercropping and short-term subsequent crop effects across European organic cropping conditions

Grain legumes are known to increase the soil mineral nitrogen (N) content, reduce the infection pressure of soil borne pathogens, and hence enhance subsequent cereals yields. Replicated field experiments were performed throughout W. Europe (Denmark, United Kingdom, France, Germany and Italy) to asses the effect of intercropping pea and barley on the N supply to subsequent wheat in organic cropping systems. Pea and barley were grown either as sole crops at the recommended plant density (P100 and B100, respectively) or in replacement (P50B50) or additive (P100B50) intercropping designs. In the replacement design the total relative plant density is kept constant, while the additive design uses the optimal sole crop density for pea supplementing with ‘extra’ barley plants. The pea and barley crops were followed by winter wheat with and without N application. Additional experiments in Denmark and the United Kingdom included subsequent spring wheat with grass-clover as catch crops. The experiment was repeated over the three cropping seasons of 2003, 2004 and 2005. Irrespective of sites and intercrop design pea–barley intercropping improved the plant resource utilization (water, light, nutrients) to grain N yield with 25–30% using the Land Equivalent ratio. In terms of absolute quantities, sole cropped pea accumulated more N in the grains as compared to the additive design followed by the replacement design and then sole cropped barley. The post harvest soil mineral N content was unaffected by the preceding crops. Under the following winter wheat, the lowest mineral N content was generally found in early spring. Variation in soil mineral N content under the winter wheat between sites and seasons indicated a greater influence of regional climatic conditions and long-term cropping history than annual preceding crop and residue quality. Just as with the soil mineral N, the subsequent crop response to preceding crop was negligible. Soil N balances showed general negative values in the 2-year period, indicating depletion of N independent of preceding crop and cropping strategy. It is recommended to develop more rotational approaches to determine subsequent crop effects in organic cropping systems, since preceding crop effects, especially when including legumes, can occur over several years of cropping.     

Phosphorus management of a rice-wheat cropping system

A long term field experiment was conducted on a sandy loam soil from 1983 to 1987 to determine how to best apply phosphorus fertilizer in a rice-wheat cropping system. The treatments included 9 combinations of phosphorus application either to both rice and wheat or to rice or wheat alone. Direct application of phosphorus at 13 kg/ha to both the crops resulted in significantly higher total productivity of the rice-wheat cropping system as compared with 26 kg P/ha applied either to rice or wheat alone. Phosphorus at 13 kg/ha for rice and 26 kg/ha for wheat was as efficient as 13 kg P/ha for rice and 13 kg P/ha for wheat. The higher rate of P (26 kg/ha) applied to both rice and wheat resulted a decline in the total productivity. The residual effects of phosphorus applied to either rice or wheat were significant to the succeeding crop but was inferior to its direct application. Phosphorus increased the leaf area index, chlorophyll content of leaves, and interception of more photosynthetically active radiation (PAR) which resulted in increased grain yield of rice and wheat. Phosphorus status of the surface soil declined markedly, in the absence of P application from 15.4 to 6.4 kg P/ha. Phosphorus applied at 26 kg P/ha to both the crops resulted a build up of the available P status of soil. Phosphorus application at 13 kg/ha to both rice and wheat maintained the phosphorus status of the soil at original level.     

Evaluation of iron pyrites as sulphur fertilizer

A field experiment was conducted for three consecutive winter crop seasons commencing in 1979–80 on the Typic Ustochrept of Pura to evaluate iron pyrites as S fertilizer. Four crops viz, wheat, chickpea, mustard and Egyptian clover were tested for their responsiveness to added pyrites. All the crops responded significantly to added pyrites. Mustard proved most sensitive to S deficiency in soil and wheat the least. Between the two legumes, Egyptian clover was more sensitive to S stress than chickpea. Average biomass production by Egyptian clover was highest followed by wheat, mustard and chickpea. Mustard and Egyptian clover required more S to achieve maximum biomass production compared with wheat and chickpea but they also recovered from the soil a large proportion of added S than wheat and chickpea. Addition of pyrites increased availability of S in soil. Pyrites enhanced mobilization of soil P and its utilization by the crops.     

Phosphorus fertilizer response in narrow-leafed lupin (Lupinus angustifolius L.) and chickpea (Cicer arietinum) compared to wheat (Triticum aestivum) in early growth

A glasshouse experiment was conducted to examine the comparative growth and P uptake response following P fertilizer application in lupins (Lupinus angustifolius L. cv. Chittick) and chickpeas (Cicer arietinum cv. Tyson) compared to wheat (Triticum aestivum cv. Sunstar). Measurements of dry matter, phosphorus uptake and nodule numbers were made at 50 and 100 days after sowing. At the 50 day harvest, the two legume crops produced less dry matter and accumulated less plant P than wheat but no such species interactions were present at the 100 day harvest. Chickpeas showed strong positive responses in nodule numbers with increasing rates of P fertilizer while such effects were less and more variable with lupins.     

Effect of N-rates on dryland wheat in relation to mulching previous crop or fallow

In many rainfed areas a rainy season crop is followed by a post rainy season (rabi) crop and the yield of the latter is directly related to the profile-stored water at the time of its sowing. Mulching is known to help increase soil moisture storage. The yields of dryland crops are also limited by availability of nutrients, particularly nitrogen. We studied the effect of organic mulching in rainy season maize or fallow on the yield of maize and the yield and water use efficiency (WUE) of the following wheat fertilized with different rates of N.Mulching increased yield of maize by 9–12% and that of the following wheat by 25–28%. The increase in wheat yield with mulching in the previous crop of maize is attributable to greater residual moisture after maize particularly in the seed-zone and enrichment of soil with nutrients. In wheat following mulched maize, the yields with 0 and 40 kg N ha^–1 were comparable to those with 40 and 80 kg N ha^–1 in the absence of mulch. For a given N rate the yield of wheat was a function of available water supply. The yield increased with water supply up to a certain level beyond which it decreased with additional water supply. The threshold water supply and the corresponding yield increased with increase in N rate. Favourable effects of mulching in maize on the yield of wheat decreased with increase in water supply. The results suggest that to achieve optimum yield of wheat in double cropping the previous crop should be mulched and the N rate for wheat should be chosen in relation to available water supplies.     

Yield response of lentil to directly applied and residual phosphorus in a Mediterranean environment

The response of lentil grown under rainfed conditions to directly applied and residual phosphorus (P) was described by a modified Mitscherlich equation, accounting for the effects of rainfall on (1) potential yield, and (2) the availability of soil-P to the crop. The response of lentil yield to directly applied and residual P was studied in two-course cereal–lentil rotational trials under rainfed conditions in a Mediterranean-type environment. Cereal crops were grown at different P application rates during 4 growing seasons at 3 sites, representing different rainfall zones in northwest Syria. Lentil (Lens culinaris Med.) was grown during 4 seasons at the same sites, each lentil crop following a cereal crop. In 3 out of 4 lentil-growing seasons, additional P was applied to lentil in subplots to compare the residual and direct effects of P application. The initial contents of extractable soil-P (P-Olsen) were low at all sites, in the range of 2–5 ppm P. Under the conditions of the experiments, lentil appeared to benefit slightly more from P applied to the preceding wheat crop (residual P) than from directly applied P. It is shown that the modified Mitscherlich equation could be used as a basis for P fertilizer recommendations for rainfed farming. As for lentil, it was concluded that a single application of P to the wheat crop in a wheat/lentil rotation could reduce the cost of lentil production, without reducing lentil yield.     

Recovery of 15N-labelled fertilizer applied to winter wheat and perennial ryegrass crops and residual 15N recovery by succeeding wheat crops under different crop residue management practices

The recovery of ¹⁵N-labelled fertilizer applied to a winter wheat (120 kg N ha^–1) and also a perennial ryegrass (60 kg N ha^–1) crop grown for seed for 1 year in the Canterbury region of New Zealand in the 1993/94 season was studied in the field. After harvests, ryegrass and wheat residues were subjected to four different residue management practices (i.e. ploughed, rotary hoed, mulched and burned) and three subsequent wheat crops were grown, the first succeeding wheat crop sown in 1994/95 to examine the effects of different crop residue management practices on the residual ¹⁵N recovery by succeeding wheat crops. Total ¹⁵N recoveries by the winter wheat and ryegrass (seed, roots and tops) were 52% and 41%, respectively. Corresponding losses of ¹⁵N from the crop-soil systems represented by un-recovered ¹⁵N in crop and soil were 12% and 35%, respectively. These losses were attributed to leaching and denitrification. The proportions of ¹⁵N retained in the soil (0-400 mm depth) at the time of harvest of winter wheat and ryegrass were 36% and 24%, respectively. Although the soil functioned as a substantial sink for fertilizer N, the recovery of this residual fertilizer by subsequent three winter wheat crops was low (1-5%) and this was not affected by different crop residue management practices.