Undersown Crops Research Articles

Effect of red clover undersowing on foliage, leaf gas exchange, and yield of spring wheat

The use of undersown plants, thanks to their favourable effect on multiple environmental characteristics, is an environmentally-friendly crop cultivation method. A valuable undersown crop is red clover, which is often grown with spring cereals. The aim of the study was to investigate the following issues: how will the cultivation of the spring wheat with undersown red clover (called intercropping) or growing spring wheat in a mixture with red clover affect the leaf gas exchange in this cereal? Will the process be modified by plant densities? Will the cultivation of the spring wheat mixture change the foliage characteristics and the wheat yield? The following parameters were studied: stomatal conductance, intercellular CO<sub>2</sub> concentration, assimilation rate, transpiration rate, limitation value, photosynthetic water use efficiency, leaf area, leaf area index, leaf mass per area, chlorophyll content, N<sub>area</sub>, P<sub>area</sub>, leaf temperature, and grain yield. It was demonstrated that the mixed sowing variant reduced the photosynthesis parameters in the leaves of wheat. In this species, a significant reduction in the stomatal conductance, intercellular CO<sub>2</sub> concentration, net assimilation rate, and transpiration rate and an increase in the limitation value and water use efficiency were noted. The wheat leaves were characterised by a higher temperature in the object with the mixed sowing variant. The wheat grain yield in the mixture was 12.6-17.5% lower than in the sole crop.

Effect of plant growth-promoting bacteria and undersown crops on the total protein content of spring barley grain grown in organic agriculture

Effect of plant growth-promoting bacteria and undersown crops on the total protein content of spring barley grain grown in organic agriculture

Effect of cover crops undersown in maize on the mycotoxin content in maize biomass

The effect of growing maize with undersown crops on the content of mycotoxins in maize biomass was studied. Small plot experiments were conducted in 2019 on two sites with different soil and climatic conditions: Žabčice and Troubsko. Three treatments of intermediate crops (Italian ryegrass; Fodder vetch and a mixture of both) were undersown into the space between the rows of maize. The maize was harvested at a dry matter content of 35% at the Troubsko experimental site and 43% at the Žabčice experimental site. After the harvest of maize, samples of green biomass (shreddings) were dried at 60°C and then analyzed for the content of mycotoxins such as deoxynivalenol (DON), aflatoxin (AF,L), and fumonisin (FUM). An average yield of maize shreddings ranged from 16.50 to 21.57 t/ha of dry matter within the individual treatment. The contents of mycotoxins from the sites differed in their statistical significance, and both experimental sites showed the lowest concentrations of AFL in maize shreddings while average concentrations of FUM and DON were always the highest. In most observations, treatments with the undersown crops reached the same values as the control treatment. Only in one treatment (mixture of Italian rye grass and Fodder vetch), an increase in the AFL content (by 0.3 µg/kg) was detected. Based on the performed analyses, it is possible to state that no adverse influence of undersown crops on the occurrence of mycotoxins in maize shreddings was recorded using the chosen methodology of cultivation. Exceeded limit values for the content of mycotoxins in feeds according to 2006/576/ were not recorded.

A guideline for spatio‐temporal consistency in water quality modelling in rural areas

A guideline for spatio‐temporal consistency in water quality modelling in rural areas

THE EFFECT OF RENOVATION OF THE PERMANENT GRASSLAND ON SOME ECONOMIC EVALUATION PARAMETERS IN CONVENTIONAL CONDITION

The aim of the research was to determine the optimum production, quality and economical evaluation of three methods of permanent grassland renovation and providing information which of the 3 legumes-grass mixtures would be most useful for restoration of permanent grassland. The studied factors investigated were: 3 ways of permanent grassland renovation use (factor I) and the 3 legumes-grass mixtures (factor II). Similar production results were obtained due to the compared methods of renovation of permanent grassland and legume-grass mixtures applied to the undersown crop of degraded permanent grassland. There was a tendency to obtain the smallest production effects and slightly higher unit costs of energy production and protein on the sward renewed by the simplified method after herbicide applied and direct sowing of the legume-grass mixtures seed with a slotted seed drill (object 3.) and when the Cent 4 mixtures was for the sward.

Effects of crop rotation and field management methods on weed density and species composition in the southeastern part of Latvia

<p class="R-AbstractKeywords"><span lang="EN-GB">Integrated weed management (IWM) is a complex approach to weed control that is based on use of several different methods complementing each other, instead of relying on one single method, like chemical weed control. Weed control methods that can be used as parts of IWM strategy include mechanical weed control, application of herbicides, low tillage, changes in the rate and application time of fertilizers, use of undersown crops and crop rotation. Weed surveys were carried out in 2013 and 2014 in the southeastern part of Latvia. The aim of this study was to assess the effect of crop rotation and other field management practices on weed density and weed species composition using the data collected in the surveys. Survey was carried out in the arable fields of conventional farms within four different size categories. One of the significant factors that explained the variation of weed composition within a field was a proportion of cereals in crop rotation within a four year period. Further surveys are required to estimate the effects of climatic variables. Density-dependence can also be important for practical management decisions for particular weed species and should be investigated.</span></p>

Yield of spring cereals in mixed stands with undersown winter turnip rape

Winter turnip rape [Brassica rapa L. ssp. oleifera (DC.) Metzg.] is an oilseed crucifer mainly grown in Nordic and Baltic countries. It can be undersown in a spring cereal as an alternative to sowing of pure stand in late July. Establishment by undersowing helps to utilize the short growing season at high latitudes. However, as undersown crops tend to affect the growth and yield of their companion crops, the effect of undersown winter turnip rape on cereal yield and quality needs to be assessed. Additionally, an evaluation of the suitability of different cereals as companion crops to winter turnip rape is required before practical recommendations can be made. The suitability of four spring cereals as companion crops to winter turnip rape was studied in three field experiments. Two-row barley, six-row barley, wheat and oat were sown at two different densities, with and without undersown winter turnip rape, sowing density depending on the density of the cereal. Undersowing winter turnip rape in a cereal did not markedly affect cereal yield. In some years six-row barley and oat with undersown winter turnip rape produced more yield than corresponding pure stands, indicating a possible facilitative effect of the undersown crucifer on the two cereal species. The results suggest that the most compatible cereals as companion crops with undersown winter turnip rape are six-row barley and oat. Mixed stand cultivation could be improved trough the identification of the optimal cereal–winter turnip rape combinations.

Investigation of biochemical and competitive effects of cover crops on crops and weeds

The weed suppressing ability and growth of 17 cover crops and undersown crops was evaluated in eleven pot and laboratory experiments. Weed suppression was greater using mulched cover crops than with undersown crops. Mulched cover crops had no effects on biomass of Hordeum vulgare and undersown crops decreased Triticum aestivum biomass in the pot experiments. Biochemical effects of various concentrations of aqueous cover crop root- and shoot-extracts were determined in the laboratory. Observed effects were inhibitory, hormetic, or combined on root growth of Lactuca sativa, Setaria viridis, Amaranthus retroflexus and Zea mays. Nonlinear dose–response functions fitted best to the data; more pronounced inhibitory effects occurred with highly concentrated plant extracts. Festuca rubra, Avena strigosa and Cannabis sativa were the cover crop species with the strongest inhibiting biochemical effect on L. sativa, maize and weeds. Active compounds and mode of action of biochemical are unknown and biochemicals from cover crop residues require research under field conditions.

Effects of repeated clover undersowing, green manure ley and weed harrowing on weeds and yields in organic cereals

Cover crops can be used to reduce leaching and erosion, introduce variability into crop rotation and fix nitrogen (N) for use by the main crops, less is however known about effects on weeds. The effects on weed seed bank, weed growth and grain yield of 4 years of annual undersown clover and ryegrass alone and in combination, and one of the 4 years with clover or clover + grass as green manure, were studied in oat and spring wheat at two experimental sites in south-eastern Norway. These treatments were compared with no undersown crop (control) and with weed harrowing. In contrast to many results in the literature, the undersown clover in this study did not suppress annual weeds, but fertilized the weeds as well as the cereals. Undersown clover resulted in a statistically significant increase of grain yield at the two sites to 116% and 121% of control. During the 4-year period relative seed bank and density of emerged weed (dominated by Spergula arvensis) increased significantly about 4.5 and 10 times respectively in the undersown clover plots at Apelsvoll. At Kise both ryegrass alone and ryegrass mixed with clover significantly suppressed the weed biomass to 70% and 74% of control respectively. It is concluded that fertilization effects of undersown clover may have dominated and overriden the competitive effects. One whole-season clover green manure did not increase the mean yield, but resulted in a significant drop in seed bank size the following year, because of limited weed establishment in an established ley. Only a slight increase in average weed biomass was observed at one of the two experimental sites. The weed seed bank and the weed biomass were essentially kept at steady state during the experimental period in harrowed plots, but harrowing decreased grain yield significantly at both sites.

The effect of soil extracts from a monoculture of spring wheat (Triticum aestivum L.) grown under different tillage systems on the germination of its seeds

The present experiment was carried out in the period 2006-2008. The aim of this study was to determine the effect of aqueous soil extracts from the soil of a spring wheat monoculture on seed germination energy and capacity, the length of the first leaf and of the longest radicle as well as the number of radicles. Moreover, the content of 0-dihydroxyphenols in the soil was compared in the last year of the study. The soil used to prepare the solutions came from a field experiment established on medium heavy mixed rendzina soil. Spring wheat, cv. Zebra, was grown using plough tillage and two conservation tillage methods in the presence of undersown crops (red clover, Westerwolds ryegrass) and stubble crops (lacy phacelia, white mustard). Germination energy of the seeds watered with the soil extracts from the ploughed plots was significantly higher than this trait in the seeds watered with the extracts from the conservation tillage treatments with spring disking of the catch crops. Germination energy and capacity of spring wheat in the control treatment watered with distilled water were significantly higher compared to the other treatments under evaluation. Spring wheat watered with the aqueous extract prepared from the soil obtained from the plough tillage treatment produced a significantly longer first leaf compared to the treatments in which both conservation tillage methods had been used. The shortest leaf and the lowest number of radicles were produced by the seedlings watered with the soil extract from the treatment with the white clover stubble crop. Radicle length was not significantly differentiated by the soil extracts under consideration. The content of 0-dihydroxyphenols in the rendzina soil determined during the spring period was higher than that determined in the autumn. The content of 0-dihydroxyphenols in the soil was lower in the conservation tillage treatments with autumn incorporation of the catch crops than in the plots in which plough tillage and conservation tillage with spring disking of the catch crops had been used. The type of catch crop used did not have a significant effect on the soil content of these compounds. At the same time, it was found that the treatments in which the catch crops had been sown tended to have higher contents of these compounds compared to the plots without catch crops.

THE INFLUENCE OF INTERCROPS AND FARMYARD MANURE FERTILIZATION IN CHANGEABLE WEATHER CONDITIONS ON CONSUMPTION VALUE OF POTATO TUBERS

The paper presents the results of research carried out over 1999-2002 with the aims to determine the influence of intercrops and farmyard manure fertilization on consumption value of potato tubers in changeable weather conditions. The following combinations of intercrops fertilization were taken into account: the control plot (without intercrop fertilization), farmyard manure, undersown crop (birdsfoot trefoil, birdsfoot trefoil + Italian ryegrass, Italian ryegrass), stubble crop (oleiferous radish, oleiferous radish – mulch). The results pointed that, the conditions of vegetation period, significantly modified the consumption values of potato tubers. The consumption value of potato tubers which were fertilized with intercrops was formed on approximated level, as the potato which was fertilized with farmyard manure. The best consumption features, especially taste, had potatoes which were fertilized with birdsfoot trefoil and with the mixture of birdsfoot trefoil and Italian ryegrass.

THE INFLUENCE OF UNDERSOWN CROPS AND STRAW BIOMASS ON YIELD AND NUTRITIONAL VALUE OF POTATO TUBERS

The paper presents the results of research carried out over 2001-2003 which aimed at describing the influence of undersown crops and spring barley straw fertilization on chemical composition of table potato tubers. Two factors were examined. I - undersown crops fertilization: control variant (without undersown crops fertilization), farmyard manure, black medic (Medicago lupulina), black medic (Medicago lupulina) + Italian ryegrass (Lolium multiflorum), Italian ryegrass (Lolium multiflorum). II – straw fertilization (subblock without straw, subblock with straw). Obtained results allow to conclude that, fertilization with mixture of black medic with Italian ryegrass and black medic in combinations without straw or with straw in terms of size and quality of yield of potato tubers it equals or it even exceeds the farmyard manure fertilization. The increase of starch, vitamin C and true protein content in comparison with control variant was noted in potato tubers fertilizerd with undersown crops biomass and straw.

WPŁYW MIĘDZYPLONÓW I NAWOŻENIA OBORNIKIEM W ZMIENNYCH WARUNKACH POGODOWYCH NA WARTOŚĆ KONSUMPCYJNĄ BULW ZIEMNIAKA

The paper presents the results of research carried out over 1999-2002 with the aims to determine the influence of intercrops and farmyard manure fertilization on consumption value of potato tubers in changeable weather conditions. The following combinations of intercrops fertilization were taken into account: the control plot (without intercrop fertilization), farmyard manure, undersown crop (birdsfoot trefoil, birdsfoot trefoil + Italian ryegrass, Italian ryegrass), stubble crop (oleiferous radish, oleiferous radish – mulch). The results pointed that, the conditions of vegetation period, significantly modified the consumption values of potato tubers. The consumption value of potato tubers which were fertilized with intercrops was formed on approximated level, as the potato which was fertilized with farmyard manure. The best consumption features, especially taste, had potatoes which were fertilized with birdsfoot trefoil and with the mixture of birdsfoot trefoil and Italian ryegrass.

The residual effect of undersown crops and nurse crops on chemical properties of light soil

The residual effect of undersown crops and nurse crops on chemical properties of light soil

Effects of undersown crops on soil mineral N and grain yield of spring barley

Undersowing a cereal crop can reduce nitrogen (N) leaching and increase available N for the successive crop. An undersown crop can also compete with the main crop. Seventeen plant species were undersown in spring barley ( Hordeum vulgare L.) to study their suitability regarding establishment, biomass production, competition with the main crop and effects on soil mineral N. Three different seeding rates were evaluated. Italian ryegrass ( Lolium multiflorum Lam.) decreased nitrate nitrogen (NO 3-N) content in late autumn and timothy ( Phleum pratense L.) in the succeeding spring. A mixture was optimal to reduce N leaching. Italian ryegrass is a very competitive species that should be undersown at moderate seeding rates to avoid large yield reduction in the main crop. Black medic ( Medicago lupulina L.) slightly increased N leaching risk, but red clover ( Trifolium pratense L.) and white clover ( Trifolium repens L.) did not increase soil NO 3-N content. As clovers did not compete strongly with the main crop, fairly high seeding rates can be used to maximise N fixation to benefit the successive crop.

Soil nitrate N as influenced by annually undersown cover crops in spring cereals

Cover crops can reduce leaching and erosion, introduce variability into crop rotations and fix nitrogen (N) for use by the main crops. In Finland, undersowing is a suitable method for establishing cover crops in cereals. The effect of annual undersowing on soil nitrate N was studied at two sites. Red clover (Trifolium pratense L.), white clover (Trifolium repens L.), a mixture of red clover and meadow fescue (Festuca pratensis Huds.), and westerwold ryegrass (Lolium multiflorum Lam. var. westerwoldicum) were undersown in spring cereals during six successive seasons, and a pure stand of cereal was grown in two years after that. In all years, the soil nitrate N was measured in late autumn, and in addition in different times of the season in last four years. The effect of undersowing on soil NO3-N content was generally low, but in one season when conditions favoured high N leaching, westerwold ryegrass decreased soil NO3-N. The negligible increase of N leaching risk in connection with undersowing clovers, associated with late autumn ploughing, supports the use of clovers to increase the cereal grain yield. The highest levels of soil NO3-N were recorded at sowing in spring irrespective of whether a crop was undersown or not. NO3-N contents were higher in sandy soil than in silt. Undersowing can be done annually in cereal cultivation either to fix or catch N. No cumulative effects on soil nitrate N were associated with undersowing after six years.;

Undersowing Legume Crops for Green Manuring of Lettuce

ABSTRACT The objective of this experiment was to investigate the potential of several species of undersown legume crops to deplete soil nitrate and to accumulate nitrogen (N). A further objective was to measure the effects of the legume crops as a green manure for a succeeding early lettuce crop. In two years, different undersown legume crops were compared with a control treatment where no crop was undersown. In November, at the end of their growing season, the legume crops reduced the content of mineral nitrogen in the top 1 m of the soil to one third of what was available when no crop was undersown. The N uptake in shoots and roots was in the range of 100–160 kg ha−1. The legume crops were incorporated at the beginning of April the succeeding year. In May, the content of soil mineral nitrogen was 3–4 fold the content in November. The main increase was seen in the top 0.25 m profile of the soils in which the legume crops had been grown. In July, the N mineralized from the incorporated legume crops and from other soil organic matter was estimated to be 36 and 38 kg ha−1, respectively. The yield of lettuce was increased by 20–45% when grown after legume green manure crops compared with the control treatment. The yield level was comparable to that obtained in conventional horticulture.

The growth productivity, and environmental impact of the cultivation of energy crops on sandy soil in Germany

Energy plants, cultivated on set-aside land, could substitute nearly 3% of the primary energy in Germany and could raise the income of farmers. However, the substitution of fossil fuels by plants requires the selection of plant species with high site suitability, an ecologically benign farming system and high yields. This paper describes results of the cultivation of 10 energy plant species suitable for combustion. Over a period of 6 yr , yield, energy gain, and environmentally relevant substances in the plant and the soil were determined under practical conditions. Fertilization was carried out in four variants each ranging from 0 to 150 kg N ha −1 and with wood- and straw ashes, as well as basic mineral fertilizer. Plant protection products were entirely dispensed with. The results show that, except for topinambur haulm (Jerusalem artichoke) and short rotation coppice with undersown crops, the mean yield ranges between 8 and 12 t DM ha −1 and that a reduction of nitrogen application from 150 to 75 kg N ha −1 causes only slight yield losses. Without fertilization, yields diminish by 20–40% after 6 years , except for poplars, which reach similarly a high yield level as with fertilization. The contents of the emission- and combustion-relevant plant nutrients, such as nitrogen, potassium, sulfur and chlorine, are significantly lower in poplars and willows than in grass, rye, triticale and hemp. Heavy metals, such as cadmium, copper, zinc, and lead, are absorbed differently. Hemp, poplars, and winter rye allow high-energy yields to be achieved. Even if nitrogen fertilization is reduced, net energy gains of more than 120 GJ ha −1 yr −1 ( 3.2 kl oil equivalent ha −1 yr −1 ) are reached.

Effect of Sowing Technique on Growth of Undersown Crop and Yield of Spring Barley

Undersowing a main crop enables establishment of a catch crop in areas characterized by a short post‐harvest period before the onset of winter. Techniques with lower costs than conventional undersowing by separate drilling are often regarded as unreliable. Undersowing by drilling after sowing spring barley (Hordeum vulgare L.) was compared with broadcast sowing simultaneously with drilling barley. Various implements were coupled behind the combined drill in cases where seed was broadcast: a press‐wheel attachment, a long‐tined harrow and a cage roller. A fourth treatment did not include an implement coupled behind the drill. The undersown crop was sown as a seed mixture of 3 kg ha–1 red clover (Trifolium pratense L.) and 6 kg ha–1 meadow fescue (Festuca pratensis Hudson). The numbers of plants and weeds and the plant height were measured five times during the growing season. Above‐ground biomass of the undersown species was determined at barley harvest and in late autumn. Grain yield of spring barley was recorded. Drilling resulted in the highest yield of undersown crop when an early summer drought occurred, but broadcasting in combination with use of seed covering equipment led to the least variation in biomass production over the 4 years the experiment was conducted. The relative proportion of meadow fescue in the crop was low in three years, and lower when broadcast than when drilled. Barley grain yield was highest when the seed was broadcast and seed covering equipment was used. Use of a cage roller increased weed biomass, but press‐wheels and a long‐tined harrow did not. Separate rolling after undersowing increased undersown crop yield in one year, but decreased grain yield in some cases.

Undersowing Italian ryegrass diminishes nitrogen leaching from spring barley

Nitrogen (N) leaching from spring barley with and without undersown Italian ryegrass was studied in Jokioinen, south-western Finland during five years (summer 1993–spring 1998) in 1.7 m deep lysimeters (Ø0.9 m) filled to 1.1 m with clay, silt, sand and peat soil. Tillage was performed in mid- October or in May, before sowing of the barley and ryegrass for the next season. In the second, third and fourth years of the experiment, total N leaching from barley without undersown ryegrass was 15, 7.9,32 and 38 kg ha-1 y-1 in clay, silt, sand and peat soil, respectively. Undersowing reduced N leaching by 52,31,68 and 27%. The reduction in N leaching from clay and sand when barley was undersown with ryegrass was nearly the same as the increased total uptake of N (barley +ryegrass).In sand soil, ryegrass was able to diminish the NO 3-N concentration of the drainage water well below the limit for acceptable drinking water. Spring tillage reduced N leaching only on peat soil (16%). Slight competition between the main and the undersown crop was indicated by lower N contents of the barley yield.;