Untersuchungen zum Einfluß von Standort, Saatstärke, N-Düngung, Sorte und Erntezeitpunkt auf den Ertrag und die Inhaltsstoffe von Zuckerhirse

Investigations into the effect of location, planting density, N-fertilization, variety and harvest date on yield and contents of sweet sorghum
Looking for high yielding plant species as renewable resources, sweet sorghum ( Sorghum bicolor [L.] Moench) seems to be an interesting crop.
In field trials at three locations in the south-west of Germany in 1983 and 1984 should be investigated the effect of N-fertilization, planting density, variety and harvest date on yield, different morphological characteristics and contents of sweet sorghum.
The results indicate that yields of 15-20 t DM/ha are only feasible when the given temperature sum is higher than 2000 °C (> 5°C). The maximum yield of 22.7 t DM/ha resp. 6.5 t/ha "Free Fermentable Sugar" (FFZ) was realized when a sufficient water supply and N-fertilization had been guaranteed.
The different possibilities of utilization of sweet sorghum e.g. as sugar crop, agricultural raw material for combustion or as forage crop urge the plant breeder to intensify the breeding efforts adapting this crop at the climatic conditions of Germany.     

Competition and Control of Volunteer Jerusalem Artichoke in Various Crops

A major production constraint in Jerusalem artichoke ( Helianthus tuberosus L.) is caused by tubers which are not recovered at harvest. Such lost tubers raise a serious weed problem the following season. Winter wheat, oat, spring oilseed rape, sugarbeet, maize and ryegrass were grown in a field which had Jerusalem artichoke as the preceding crop in order to obtain information about their competitive ability and the efficacy of various control measurements against Jerusalem artichoke infestation. The Jerusalem artichoke treatments in these crops were: total control by regular hand weeding (TOC), mechanical/chemical control (MCC), and no control (NOC). Under the NOC treatment, Jerusalem artichoke infestation at harvest was variable among crops, with the number of shoots ranging from 9 to 25 m⁻² in oat and maize stands respectively. The number of Jerusalem artichoke shoots in the MCC plots was reduced by 50 to 99 % in oat and maize, respectively. The highest crop yields in each of the six species were realized under the TOC treatment. Insignificant yield reductions were observed in the NOC treatment of wheat, oat, rape and ryegrass. However, under this management yield reductions of 91 and 81 % occurred in sugarbeet and maize respectively. Depending on the preceding crop, 1–9 shoots m⁻² of Jerusalem artichoke were still recorded under the MCC plots in the following season. Consequently, for complete elimination of infestation, volunteers must be controlled in the second and probably in the third year following a Jerusalem artichoke crop.     

Optimale Stickstoffdüngung aus ökonomischer Sicht in Abhängigkeit von Standort, Vorfrucht, Bodenbearbeitung, Phosphat- und Kalidüngung sowie Sortenwahl

Economically optimal N-fertilization as influenced by location, preceding crop, cultivation of soil, phosphatic and potassic fertilization and choice of variety.
– The economically optimal quantity of N-fertilization is mainly influenced by location, preceding crop, cultivation of soil, phosphatic and potassic fertilization and choice of variety. The optimal organization of these factors, however, to the extent that it can be influenced by the farmer, is a precondition of an effective N-fertilization.
– Depending on the above-mentioned factors the economically optimal quantity of N-fertilization shows a great variation. In the majority of cases the optimal N-quantity to winter wheat ranges between 100 and 180 kg/ha and to sugar beets between 120 and 200 kg/ha.     

Harvest Dates, Fertilizer and Varietal Effects on Yield, Concentration and Molecular Distribution of Fructan in Jerusalem Artichoke (Helianthus tuberosus L.)

In a pot experiment two varieties of Jerusalem artichoke ( Helianths tuberosus L., cv. Topianka and cv. Violet de Rennes ) were exposed to different supplies of N, P and K. Nitrogen supply increased tuber yield more than the productivity of aerial parts. Violet de Rennes responded better to N than Topianka. Nutrient regimes without P or K addition but including N to some extent depressed the yields of tubers only (by 8–23 %). Carbohydrate concentrations (78–81 % of d.m.) and molecular fructan distributions were neither influenced by fertilizer regimes nor by mineral concentrations in the tubers.
Genotypic differences were significant for yield, for concentrations of N, P, Ca, S and Cu, and for fructan concentration in the tubers. At harvest time the fructose/glucose ratio in tubers of Violet de Rennes was about 10 % higher than in Topianka and remained on a higher level during storage.
Harvest time had the greatest influence on carbohydrate composition. Depolymerization of fructan proceeded at a high rate in November and slowed down during subsequent storage, accompanied by a decline in polydispersity. Simultaneously osmolanty increased, resulting in a freezing point depression of < 0.5 °C.     

The Effect of Preceding Crop and Pre-Sprouting on Crop Growth, N Use and Tuber Yield of Maincrop Potatoes for Processing Under Conditions of N Stress

Factorial field trials were carried out on an experimental farm near Kassel, Germany, in two consecutive seasons (2003 and 2004) in order to examine the impact of leguminous and cereal preceding crops (i) on soil N availability under subsequent potatoes and (ii) the effect of preceding crop and pre‐sprouting of seed tubers on crop development, N uptake, N utilization efficiency and total and size‐graded tuber yields relevant for processing into either crisps or French fries. In addition, an approach to analyse complex field experiments using mixed models is discussed. Soil mineralized nitrate‐N at emergence of the potato crop was affected by the preceding crop and was highest when potatoes followed peas, while the short‐term alfalfa/grass/clover ley appeared too sensitive to environmental conditions in the preceding cropping season, and its efficiency in terms of N supply may be hard to predict. Pre‐sprouting advanced crop development and dry matter accumulation of the canopy, translocation of assimilates and N from canopy into tubers and allowed an increased N utilization efficiency. The positive effect of pre‐sprouting on total tuber yield was compensated up to the final harvest, but a higher percentage of marketable tuber yield for French fries (>50 mm) was found independently of the date of harvest. An increasing N supply (after peas and a following catch crop) may be efficient in terms of higher yields of the marketable size‐grades (40–65 mm) for crisps, but increase oversized tuber yields in seasons not affected by Phytophthora infestans. Average tuber fresh weight responded consistently and positively to seed‐tuber preparation (pre‐sprouting), cultivar (cv. Agria) and an increased N supply (after peas).     

Wirkung von Impfung, N-Spät-, PK-Düngung und Beregnung auf den Kornertrag und die N-Akkumulation in den Samen von mehreren Sojabohnensorten an zwei Standorten Deutschlands

Effect of inoculation, late N- and PK-manuring and irrigation on seed yield and N-accumulation in the seed of several varieties of soybean at two locations in Germany
Effect of inoculation with rhizobium, late N- and PK-fertilization and irrigation on yield and N-accumulation in seeds of four soybean cultivars was tested in a polyfactoral experiment design.
Seed yield ranged from 11.5 to 43.7 dt DM/ha and N-accumulation in seeds from 52 to 247 kg/ha. Irrigation and inoculation were the most effective production techniques. Cultivar MA96 yielded 38.0 dt DM/ha in Frankenthal on a sandy soil when plants were irrigated and inoculated. No further yield increase was obtained with additional NPK-fertilization. Cultivar KW269 resulted in a significant higher yield (43.7 dt DM/ha) when late N-fertilization was given to irrigated and inoculated plants.     

Vorfruchtwirkungen verschiedener Blattfrüchte auf Winterweizen und Einfluß von Anbaumaßnahmen

Effects of preceding "break crops" on winter wheat and influence of cultural practices
Between 1979—83 there was tested the effect of 5 "break crops" (biennial alfalfa, clover-grass, faba bean, winter-rape, silomaize) on succeeding winter wheat and the interaction with changed cultural practices such as N-fertilization and conventional or reduced primary tillage (plough ↔ rotary tiller).
After the break crops wheat yield decreased within a range of 4 dt/ha as follows: alfalfa → beans → rape/ clover-grass/maize. Raising N-fertilization hardly allowed to improve the value of the break crops; most likely that of maize and with rotavating. Adaption of N-dressings promised greater influence.
The manner of primary tillage exerted stronger influence on the yield than the level of N-fertilization. Concerning long-term yield the rotary tiller equaled the plough after 4 break crops; after faba bean it was superior. Increasing N-fertilization tendentially favoured the rotary tiller after bean, rape and maize. Using the rotary tiller, at beginning of growth there may be calculated on 15 % higher NO₃-values and/or higher N-mineralization or N-transformation.
Eyespot disease could not be prevented sufficiently and purposefully by an other break crop, N-fertilization or primary tillage. Recurrent rotavating suppressed weed less than ploughing.     

Stickstoffausnutzungsvermögen von Lolium perenne und Lolium multiflorum-Sorten

Selection for improved nitrogen-utilization in Lolium
In a 3-year study the responses of 14 Lolium perenne-varieties and 14 of Lolium multiflorum to different nitrogen fertilization (75, 150, 300 kg N/ha) were investigated. The varieties were classificated into four types of nitrogen utilization. "Low input varieties" can be found in type III. The varieties of this type produced always the highest yield at all levels of nitrogen fertilization. The yield of type I was always smaller than the average of all varieties. The varieties of type II gave significant better responses than the trial average up to 150 kg N/ha. Under low and high N-fertilization the type III can be separate of type I and II because it is always the outstanding variety. The dry matter production of the roots did not show varieties differences under the increasing N-fertilization. The soil nitrate contents were with 20 kg nitrate nitrogen per ha very small.     

Einfluß der Bestandesdichte auf Ertrag und Qualität der Zuckerrübe bei unterschiedlichem Erntetermin

The effect of plant population on yield and quality of sugar beet at different harvesting date
Optimum plant population of sugar beet in respect of corrected sugar yield in Central Europe ranges from 70 000 to 90 000 plants/ha. It is known that extending the length of growing period by later harvesting causes an increase in yield and quality of sugar beet depending on location and weather. There is a lack of information, however, about the effect of plant population on yield and quality increase with postponed harvesting date.
The objective of this study was to investigate the influence of plant density and harvesting date on yield and quality of sugar beet.
Four trials were carried out at Göttingen (Lower Saxony) from 1982 to 1985 which included each year four plant populations and three harvesting dates (end of September to middle of November).
Depending on seed lot, plant spacing and field emergence, plant populations varied between 87 000 and 27 000 plants/ha. Averaged over the years, the plant populations for the different treatments reached 71 000, 51 000, 40 000 and 31 000 plants/ha.
Later harvesting date and increasing plant population resulted in higher yield of beet and/or higher sugar content of beet. The increase in corrected sugar yield with extending the length of growing period was highest in plant populations with high density.
From the results it can be concluded that by having the choice, a beet crop with the highest plant population should be harvested at the end, a crop with a lower plant population at the beginning of the harvesting period, unless there have to be observed some other aspects (location, crop sequence, field condition).     

Zur Eignung des Kornguts unterschiedlich stickstoffgedüngter Getreidebestände als Rohstoff für die Bioethanolproduktion

The Suitability of Grains from Cereal Crops with Different N Supply for Bioethanol Production
The properties of grains of different small grain cereals, produced under increasing N-supply levels, for conversion into bioerhanol were investigated. Grain material of winterwheat, -rye and -triticale, two cultivars each, was used At two locations, field experiments comprising several N-fertilization levels between 0 and 180 kg N/ha were conducted. The main parameters analysed were the bioethanol output (1 bioethanol/dt grain dry matter) and the bioethanol yield (1 bioethanol/ha), both under addition and without addition of technical enzymes. Furthermore, the falling numbers, the protein content and die autoamylolytic quotient (AAQ) were determined. AAQ means the autoamylolytic bioethanol output related to die output under addition of technical enzymes. With a rising N-supply, yields/ha and die protein contents of grain increased differently. Combined with increasing protein contents, decreasing bioethanol outputs were measured, particularly with wheat, to a smaller extent with triticale, and to an even lesser extent with rye. Only with wheat were die AAQ-values significantly reduced as a consequence of rising N-supply levels. In interaction with growing conditions, cultivars and N-levels, the bioethanol yields/ha of rye and triticale equalled or even surpassed the yields of wheat, particularly under autoamylolytic-conversion processing conditions.     

秸秆还田下两种氮肥施用方式对夏玉米生长特性的影响

氮肥施用过量、肥效低下以及持续增产效果不显著一直以来制约着农业的发展。近年来,秸秆还田配施氮肥在农业生产中已经得到了广泛应用。本试验在向当地农户调查的基础上设置了传统施氮处理(300kg／hm^2),依据叶片诊断技术所确定的玉米需肥量设置了优化施氮处理(60kg／hm^2),以不施氮肥作为对照,研究了北京郊区秸秆还田下不同氮肥施用方式对夏玉米生长特性以及产量的影响。通过田间试验,得到如下结果：两种氮肥施用方式对夏玉米株高、叶面积、茎粗、节根等影响不明显;各指标均高于对照;传统施氮、优化施氮条件下夏玉米产量分别达到7297．65kg／hm^2、7385．1kg／hm^2,产量效应几乎没有差异;然而对照处理只有5485．65kg／hm^2,传统施氮、优化施氮增产达到了33．03％和34．63％;优化施氮大大减少了氮肥使用量,不仅具有良好的经济效益,而且具有良好的生态效益。     

Evaluation of Certain Sugarcane Varieties for Ethanol Production

Field experiment was conducted to study the ethanol yielding ability of twenty-three sugarcane varieties during 1987–88 at Sugarcane Breeding Institute, Coimbatore, India. Among the varieties studied, Co 8145 yielded the highest quantity of ethanol (13,619 1/ha) and Co 1305 yielded the lowest (5,579 1/ha). Apart from Co 8145 , varieties CoSi 86071, Co 6304, Co 975 and Co 7219 were also found promising which yielded alcohol above 12,000 1/ha. Total sugars had a positive association (r = 0.974**) with fermentable sugars in juice. Ethanol yield per unit volume of juice (actual yield) had a significant positive association with total sugars (r = 0.818**) and fermentable sugars (0.942**) in cane juice. Cane yield had a direct bearing on ethanol yield as evidenced from the highly significant positive correlation between them (r = 0.890**). Hence a variety meant for ethanol production should contain high total and fermentable sugars in juice coupled with high cane yield and juice extraction per cent. These high yielding ethanol varieties viz., Co 8145, Cosi 86071, Co 6304, Co 975 and Co 7219 may be exploited for commercial production of ethanol directly from juice and used as parents for evolving cane varieties meant for ethanol production.     

N-Dynamik des Bodens, Ertragsbildung und Stickstoffentzug von Winterweizen bei unterschiedlicher Höhe und Verteilung der mineralischen N-Düngung

NO₃ dynamics in the soil, yield formation and N uptake of winter wheat as influenced by dosage and distribution effects of N-fertilizer application
In a 4 year series of field trials carried out with 9 regimes of nitrogen fertilizer application at two trial sites with rather shallow top soil layers but large deviations in soil characteristics, grain yield varied between 50 dt/ ha and 120 dt/ha with nitrogen doses from 0–170 kg N/ha. Soil nitrogen supply for wheat grain formation on unfertilized plots reached 80 kg N/ha/year within the narrow range of 75–95 kg N/ha in different years at both sites which amounts to 1.5 % and 0.5 % of the highly different N-content of the trial sites.
The most successful nitrogen application regimes are characterized by modest fertilizer doses in early spring and the delay of supplemental fertilizer doses until growth stage EC 32. They resulted into modest NO) soil content from EC 29 to EC 32 and/or a noticable decrease of soil NO₃ content during growth stage EC 30–32, which seems to be responsible for the development of only modest stand densities and reduced straw yield, while the delayed supplementation with nitrogen fertilizer overcompensated these effects mainly by increased grain numbers/ear and a remarkable improvement of harvest index.
The contribution of soil borne nitrogen to kernel yield formation started to decrease with even low dosages of supplemental nitrogen fertilization with the exception of the highest yielding season 1987/88. Top levels of grain yield have been regularly obtained with supplemental nitrogen fertilizer dosages about 40 kg N/ha below grain yield nitrogen extraction if they were added within favorable application regimes.     

Variance component estimations and allocation of resources for breeding sweetpotato under East African conditions

In Africa, average sweetpotato storage root yields are low and breeding is considered to be an important factor in increasing production. The objectives of this study were to obtain variance component estimations for sweetpotato in this region of the world and then use these to determine the efficiency of variety trials and breeding systems. From an incomplete series of variety trials in Kenya and Uganda (comprising 15 genotypes, three locations, two crop durations and three seasons) variance components were estimated ‐ using the REML method ‐ for the following traits: storage root yield, biomass production, harvest index, storage root dry matter and the Elston index which was used to aggregate all four traits. The storage root yield of clones across all 12 environments ranged from 15.2 to 33.0 t/ha. The variance components were significant for all traits, except the genotype by season interactions for storage root dry matter. The efficiency of selection systems was determined for total test capacities of 450 and 900 plots and using not more than five locations. Two‐stage selection was 17‐81% more efficient than one‐stage selection after two seasons of testing. Two‐stage selection was optimized under the restriction of using at least two locations at step 1. Trials with two locations and one replication at step 1 and five locations and two replications at step 2 were appropriate both for selecting for storage root yield and for simultaneously selecting for storage root yield, biomass production, harvest index and storage root dry matter content by using the Elston index. There are indications that such an allocation of resources for breeding sweetpotato is also appropriate for other regions in Sub‐Saharan Africa.     

Erhaltung der Ertragsfähigkeit des Bodens auf lange Sicht unter dem Einfluß von Fruchtfolgegestaltung, Düngung und Herbizideinsatz

Impact of crop rotation, fertilizer treatments and herbicidal applications on the long term maintenance of soil fertility
V. Comparative studies regarding chemical and physical factors of the yield potential of a soil over a ten year experimental period
In order to examine the influence of different crop management practices such as crop rotation, fertilizer treatments and herbicide applications on the yield potential of a soil, the Crop Science Department of the Swiss Federal Institute of Technology (ETH Zurich) conducted a long term field experiment commencing 1973. The experimental location was at the Swiss Federal Research Station for Farm Management and Agricultural Engeneering at Tanikon/TG (northeastern Switzerland).
After the ten year period, chemical and physical soil properties were not found to be substantially affected by the various experimental treatments. Organic carbon and total nitrogen were more influenced by fertilizer treatments than by crop rotation and herbicide applications. Both cation exchange capacity and pH proved to be fairly stable values.
Aggregate stability and organic matter exhibited similar profiles, although soil bulk density was affected by crop rotation. The volume of large and medium sized pores was similarly affected in that the corn-dominated crop rotation resulted in a quantifiable impact upon soil compaction.
Depending upon weed control efficiency, the grain yields of the winter wheat test crop clearly exhibited the effects of crop rotation whereas the lowest yields resulted from the corn-dominated crop rotation.     

Genotypic variability and genotype by environment interactions for inulin content of Jerusalem artichoke germplasm

Genetic variations in germplasm and genotype × environment interaction (G × E) are important for crop improvement. The objectives were to explore genetic variation in Jerusalem artichoke germplasm and to evaluate G × E interaction for inulin content. Seventy-nine accessions of Jerusalem artichoke were evaluated in a randomized complete block design with two replications for three seasons. Significant variation in inulin content (55.3–74.0% dry weight) was observed and the genotypes with high inulin content could be identified although there was intermediate G × E interaction. Genotypes were also significantly different for days to maturity, fresh tuber yield, biomass and harvest index and G × E interactions for these traits were also significant. The correlation between inulin content and days to maturity was not significant (r = −0.20), whereas inulin content and fresh tuber yield were significantly associated (r = 0.22). JA 37 and CN 52867 are promising for high yield and inulin content.     

滨海盐碱地中垄作模式对菊芋生长及养分吸收的影响

菊芋具有很强的环境适应性,种植菊芋对改良滨海盐碱地并提高土壤固碳量有很大的潜力。为了提高菊芋在滨海盐碱地中的生物量及固碳量,采用垄作模式栽种,探讨菊芋的生长及土壤养分吸收过程,从而为更好地种植菊芋提供依据。结果表明,垄作处理可显著提高菊芋产量、生物量及养分吸收量,菊芋产量可提高约15%,全株干物质量提高47%,生物固碳量提高29%。垄作模式有利于滨海盐碱地中菊芋产量提高与固碳量增加。     

Strahlungsnutzung durch Bestände ölreicher Körnerfruchtarten — Winterraps, Öllein und Sonnenblume im Vergleich

Radiation use by oil seed crops — a comparison of winter rape, linseed and sunflower For the production of grain crops rich in oil, winter rape, linseed and sunflower are similarly suitable at many arable locations. We wanted to compare the extent to which radiation (PAR) is intercepted and utilized by the individual species for dry matter and yield production. For this purpose, a 2‐year field experiment comprising the factors genotype, N fertilization and soil tillage was conducted. For five phases of crop development, growth rates (CGR, RGR and NAR) and PAR utilization were calculated. At full ripeness, total dry matter, grain, oil and energy yields, the crop‐ and year‐specific PAR supply, its interception and utilization for dry matter production and the resulting energy binding were determined. Due to the different individual vegetation periods, the PAR supply of the crops differed. The crop assimilation areas also differed, with values for winter rape and sunflower higher than those for linseed. The yield productivity of winter rape and sunflower was also higher than that of linseed. N fertilization increased yield to different extents for the different crops. On average, winter rape and sunflower produced the same amounts of dry matter and energy yield. Due to a higher harvest index, sunflower had the highest grain yield, and because the oil concentration in grain was comparatively high sunflower produced the highest oil yield, too. Under cool and wet climate conditions, however, the productivity of sunflower is offset by a relatively high yield risk because of uncertain ripening. The highest PAR utilization by linseed did not compensate for its very short vegetation period in combination with the lowest PAR interception.     

Effect of environmental variables on performance of Jerusalem artichoke (<Emphasis Type="Italic">Helianthus tuberosus</Emphasis> L.) cultivars in a long term trial: a statistical approach

Tuber yield, together with tuber number and size are the basic agronomic and breeding traits in Jerusalem artichoke and can be significantly affected by environmental factors. We report the results of a long term trial on the performance of 20 Jerusalem artichoke cultivars. The random model for means with restricted maximum likelihood (REML) procedure was used to estimate the overall effects of the genotype, environment and genotype by environment interaction on traits. The partial least square regression (PLSR) model was used for modeling genotype by environment interaction variance components with a set of available correlated environmental variables. The REML variance component estimates model revealed that tuber number and yield are more dependent on GE interaction which allowed identification of best genotypes for specific environments. The PLSR model revealed that the most important climatic variables for optimal emergence, canopy development, high tuber number and yield are adequate soil and air temperatures in April. For larger tuber mass, precipitation variables and even distribution of rainfall were the most important factor, together with soil and air temperature in June when tuber growth is initiated. The knowledge obtained in this study is valuable for the identification and understanding of key environmental factors that contribute to the performance of Jerusalem artichoke.     

Die Ertragsentwicklung von Wintergetreide und Zuckerrüben bei dauerhafter Senkung des N-Düngungsniveaus

Effects of Long-term Fertilizer N Reduction on Winter Grain and Sugar Beet Yields
The results of recent field experiments concerning the effect of long-term N-reduction on the yield and quality of sugar beet, winter wheat and winter barley on plots which had previously had received ample amounts of N are studied in this paper.
The yield and quality of crops harvested on plots where N-dressings had been reduced for 6–8 years were similar to those of crops grown on plots where N-application had been reduced for only 1 year. Grain yield of winter wheat and winter barley grown without any N-application decreased to about 60 % of amounts normally harvested under local conditions with recommended N dressings, whereas the white sugar yield still remained at 90 %. The yields decreased slightly with an increase in the duration of the experiments. Yields of both cereals and beets remained constant within each level of fertilization, even 6 years after inition of trials with 50, 75 and 125 % of locally recommended N dressings.
On plots that did not receive nitrogen fertilization, N-contents of grain were between 1.5 and 1.7 % for winter wheat and 1.0 and 1.6 % N for winter barley. These contents remained constant over a trial period of 6 years. The amount of annual export of 55–91 kg N/ha also remained constant. Limited N availability causes a decrease in grain protein content rather than in grain yield.
Compared to winter grain species, sugar beet (with 74–117 kg N/ha in the beet body) could realize the highest annual export of nitrogen from the plot. Differences in annual N export existing between the various locations of the plots cannot be explained by differences in soil quality. Continuous high yields that were found even without any N-dressings may be explained by asymbiotic N-fixation, deposition of atmospheric N and a progressive decrease in soil N with 17–56 kg N/ha removed from soil resources annually.