RESEARCH INTO THE AFTER-EFFECT OF UNDERSOWN INTERCTOPS AND STRAW ON WINTER TRITICALE

Anna Płaza¹, Feliks Ceglarek², Danuta Buraczyńska^2
1 Department of Agrotechnology, Faculty of Natural Science, Siedlce University of Natural Sciences and Humanities, Poland
² Department of Plant Cultivation, University of Podlasie in Siedlce, Poland

ABSTRACT

The present paper presents the results of research carried out over 1998-2001 which aimed at defining the after-effect of undersown intercrops and straw on the degree of weed infestation and yielding of winter triticale. The experiment involved two factors: I - fertilization with undersown intercrop (control, manure, birdsfoot trefoil, birdsfoot trefoil + Italian ryegrass, Italian ryegrass); II - potato fertilization with barley straw (without straw, with straw). In the first year after organic fertilization table potatoes were cultivated, and in the second year - `Tornado´ cultivar winter triticale. The lowest weed infestation was recorded in the field of winter triticale for the forecrop fertilized with a mixture of birdsfoot trefoil with Italian ryegrass. Potato fertilization with undersown intercrops and barley straw showed a positive after-effect on the grain yield, grain yield structure components, straw yield and total protein yield of winter triticale grain. The highest grain yields, of the highest grain yield structure components values, straw yield, as well as total protein yield of grain were obtained from winter triticale cultivated after potato, under which a mixture of birdsfoot trefoil with Italian ryegrass and barley straw were ploughed-in.

Key words: after-effect, undersown intercrop, straw, winter triticale, weed infestation, yield.

INTRODUCTION

An integrated cultivation system uses, in a harmonious and balanced way, a technical and biological advancement in plant cultivation. All that makes it possible to incorporate both the economic and ecological aims. In that production system it is recommended to saturate the crop rotation with intercrops to be ploughed-in as green manure allowing for high crop yields and being favorable for the protection of the natural environment [7,8,18]. Under the current economic conditions of Polish agriculture, an alternative source of biomass can be also made up by straw remaining in the field after cereal harvest, which can be applied together with undersown intercrops. Organic fertilizers are perfectly used not only by potato cultivated directly after their ploughing-in, but also by the successive crop. Although the effect of manure on the yielding and weed infestation of successive crops was researched by numerous authors [3,12,16,22], there is a lack of experimental data evaluating the after-effect of undersown intercrops and barley straw.

After potato cultivated on organic fertilizers, it is recommended to sow winter crops, cereals which limit nutrients leaching, nitrogen especially [7]. Here one can sow winter triticale, cereal of high grain feeding value whose cultivation has been recently launched.

Field weed infestation is an important element which determines successive crop yielding; it can be limited by cultivating intercrops. It appears that undersown intercrops decrease the weed infestation of successive crops, and decrease their yield [6,12,16]. The contemporary agricultural literature offers few experimental data defining the reaction of winter triticale to the after-effect of undersown intercrops and straw. The present working hypothesis assumes that potato cultivated after ploughed-in undersown intercrops and barley straw has an adverse effect on the degree of weed infestation and winter triticale yielding. All that calls for further research which would aim at defining the after-effect of undersown intercrops and barley straw on the degree of weed infestation and yielding of winter triticale cultivated after potato.

MATERIAL AND METHODS

The field experiment was carried out over 1998-2001 at the Zawady Agricultural Experiment Station (RSD) of the University of Podlasie in Siedlce. The research was carried out on a very good rye complex soil, of neutral pH and a low richness in phosphorus, potassium and magnesium. The content of humus accounted for 1.15%.

The experiment was set up as a split-block design in three replications, on plots of harvest area of 15 m². The following two factors were investigated:

1. Potato fertilization with undersown intercrop:

1. control (without organic fertilization),

2. manure (30 t.ha^-1),

3. Birdsfoot trefoil (Lotus corniculatus L.) (21.2 t.ha^-1),

4. Birdsfoot trefoil + Italian ryegrass (Lotus corniculatus L. + Lolium multiflorum L.) (27.4 t.ha^-1),

5. Italian ryegrass (Lolium multiflorum L.)(33.4 t.ha^-1).

2. Potato fertilization with straw:

1. without straw,

2. with straw.

Undersown intercrops were sown in spring barley cultivated for grain. During barley harvest the straw yield was determined; it accounted for an average of 5.9 t.ha^-1. As for the plots with shredded straw, the straw was left, and as for the plots without straw - it was collected and taken away from the field. In all the combinations with straw, except for undersown birdsfoot trefoil, a complementary nitrogen dose at the amount of 0.7 kg per 100 kg of straw was applied. In autumn all of the biomass of intercrops was ploughed-in to become green manure.

The amount of macroelements (kg.ha^-1) contained in the organic fertilizers used was as follows: manure (168.2 N; 51.3 P; 144.7 K), barley straw (42.3 N; 18.9 P; 100.8 K), birdsfoot trefoil (157.6 N; 36.8 P; 134.7 K), birdsfoot trefoil + Italian ryegrass (169.3 N; 38.9 P; 148.8 K), Italian ryegrass (141.0 N, 35.9 P; 140.5 K).

In the first year after organic fertilization table potatoes were cultivated, while in the second year - `Tornado´ cultivar winter triticale. After potato harvest phosphorus and potassium fertilizers were spread; the amount of fertilizers per 1 ha amounted to: 60 kg of P₂O₅ and 70 kg of K₂O. Winter triticale was sown in the third decade of September at the amount of 220 kg.ha^-1. In spring when the vegetation period started, the plantation was harrowed and fed with nitrogen (40 kg.ha^-1). The second dose of nitrogen (30 kg.ha^-1) was applied at the shooting stage. The intensively growing weeds were sprayed with Apyros 75 WG herbicide at the dose of 26.5 g.ha^-1.

Right before winter triticale harvest, from each plot from the area of 0.5 m² weed samples were taken with the quantitative and qualitative method in order to determine their species composition, number and air-dry matter. Then ears were counted and their control samples were taken to determine the number of grains per ear per 1 m². Winter triticale was harvested at the full ripeness of grain (in the third decade of July). During harvest there were determined both the grain yield at the moisture of about 13% and the straw yield. For laboratory determinations, grain and straw samples were taken from each plot. The 1000 grain weight was determined with an electronic seed counter and weighed using the laboratory balance. The content of total nitrogen in grain and straw of winter triticale was determined with the Kjeldahl method. The content of total protein was calculated multiplying the content of total nitrogen by the coefficient of 5.83. The total protein yield is defined by the product of the content of total protein and the grain or straw yield. Each of the characteristics was variance-analyzed following the split-block design. In case of significant sources of variability, a detailed comparison of means was carried out with the Tuckey test.

RESULTS AND DISCUSSION

Reports on the susceptibility of winter triticale to weed infestation are scarce and ambiguous. The research carried out showed that that the dry matter of weeds defined prior to winter triticale harvest was significantly modified by the experimental factors and their interactions (Fig. 1). Potato cultivated after ploughed-in undersown intercrops helped the reduction of dry matter of weeds in winter triticale field by an average of 69.6%, as compared with potato cultivated without fertilization with undersown crop and by 29.6%, as compared with potato cultivated with manure. Similar weed control effects caused by intercrops are reported by other authors [4,6,11,12]. Pawłowski and Woźniak [12], however, showed an increase in the number and weight of weeds in winter triticale field in the second year after manure, as compared with the ploughed-in undersown crop. Similar effects of manure application under the forecrop of winter rye and spring barley are reported by Blecharczyk [3]. In the present research significantly lowest weed weight was noted for winter triticale cultivated after potato, under which undersown birdsfoot trefoil with Italian ryegrass was applied. All that comes from the fact that the mixture producing a large amount of biomass creates a close stand, and thus inhibits the development of weeds and shows a favorable effect on the growth and development of crops cultivated as a link of crop rotation (undersown crop - potato - winter triticale). Also ploughing-in barley straw under potato also helped limiting the weed infestation in winter triticale field. The interaction of the factors researched shows that adding straw both to undersown intercrops and to manure significantly decreased the weed weight; it is due to a greater amount of biomass and macroelements introduced into soil as a result of a combined application of organic fertilizers. Under such conditions both potato and the successive crop, namely winter triticale, are becoming more competitive towards weeds.

Undersown intercrops and barley straw applied under potato reduced not only the weight but also the number of weeds (Fig. 2). Significantly lowest number of weeds was noted in winter triticale cultivated after the forecrop of a mixture of birdsfoot trefoil with Italian ryegrass, as well as after Italian ryegrass. Similarly the application of straw under potato resulted in a decreased number of weeds (by an average of 6 pieces.m^-1) in winter triticale field as compared with no-straw treatment. It is a result of better habitat conditions for winter triticale cultivated in the second year after fertilization with undersown crop, manure and straw. However the greatest number of weeds was recorded in winter triticale cultivated after potato under which no organic fertilization was applied. Although winter triticale shows considerably competitive towards weeds, such competitiveness depends on agronomic conditions [8,11,12].

In the present experiment involving winter triticale cultivated as the control the following weed species dominated: field violet, wind grass and field pennycress. Ploughing-in undersown intercrops and manure under potato, being the forecrop of winter triticale, limited the weed number (Table 1). The greatest weed reduction was recorded in winter triticale cultivated after the forecrop of the mixture of birdsfoot trefoil with Italian ryegrass and after Italian ryegrass. Parylak [11], however, does not report on a significant effect of the kind of the intercrop ploughed-in on the variation in the dominant weed species. Fertilizing with straw applied under the forecrop of winter triticale also limited the dominant weed species (wind grass, field violet, and field pennycress), however less considerably than ploughing-in undersown intercrops (Table 2). Again a well-known rule is confirmed; the number of weeds in the cereal field is most limited by intercrops applied under the forecrop [3,11,12,17].

The statistical analysis showed a significant after-effect of potato fertilization with undersown intercrop and barley straw and their interaction on the winter triticale grain yield (Fig. 3). Ploughing-in undersown intercrops under potato increased the successive crop grain yield by 35.2%, as compared with the grain yield noted for the control on which triticale was cultivated after potato without organic fertilization. Significantly highest grain yield was collected from winter triticale fertilized under the forecrop with the mixture of birdsfoot trefoil with Italian ryegrass. Similarly in the reports by Małecka [8] the highest grain yield was obtained from winter triticale cultivated in the second year after stubble intercrop applied in a form of a mixture of oat with pea. However the reports by Miczyński and Siwicki [9] and Batalin et al. [1] show that the highest increases in the successive crop grain yield were obtained for green manure of red clover or its mixture with alfalfa and for manure. A favorable after-effect of manure applied under winter triticale forecrop is also reported by Woźniak [22]. In the present research the after-effect of manure expressed as the grain yield did not differ significantly from the after-effect of Italian ryegrass, however it was significantly higher than that of birdsfoot trefoil. It is due to the fact that the fertilizer which resulted in a higher potato yield also showed a better after-effect, however not in every case. Birdsfoot trefoil showed a higher nutritive value for potato cultivated in the first year, and a lower after-effect on winter triticale in the second year. According to Nowak [10], papilionaceous plants ploughed-in for green manure, due to the narrow C : N ratio, mineralize in soil faster. For that reason the nutrients released are first of all used by the plant cultivated directly after their ploughing-in, and less considerably by the successive crop. To prevent it, papilionaceous plants to be used for green manure should be sown in mixtures with grasses. Adding a non-papilionaceous plant into the mixture increases the C : N ratio and slows down the process of mineralization of the biomass ploughed-in. Under such conditions nutrients are more effectively used both by potato cultivated in the first year and by the successive crop. All that is confirmed by the results of the present research. Fertilization with straw also showed a favorable after-effect on winter triticale grain yield, especially a combined ploughing-in of straw with the mixture of birdsfoot trefoil with Italian ryegrass. Following the application of these forms of fertilization, there was noted a significantly highest grain yield. A favorable after-effect of additional organic biomass introduced into soil is also emphasized by other authors [1,5,11,14,18,20,21].

The winter triticale grain yield depends mostly on the yield structure components significantly affected by the experimental factors and their interaction (Table 3). The best after-effect on winter triticale grain characteristics was recorded for the mixture of birdsfoot trefoil with Italian ryegrass. In case of treatments which involved ploughing-in Italian ryegrass or manure under potato, the number of ears prior to successive crop harvest, the number of grains per ear and 1000 grain weight did not differ significantly. Reports by Woźniak [22] also show a favorable after-effect of undersown intercrop or manure ploughed-in under winter triticale forecrop on the grain yield structure components. Małecka [8] showed that the number of ears prior to harvest and 1000 grain weight of triticale cultivated in the second year after the mixture of oat with pea and after white mustard were significantly higher than those of the control, without intercrop. Also in the present research the parameters defining the grain yield structure of triticale cultivated in the second year after ploughing-in birdsfoot trefoil were higher than those of the control, without organic fertilization. In the present experiment, just like in those reported by Puła and Łabza [13], fertilization with straw applied under cereal forecrop resulted in a significant increase in the number of ears, number of grains per ear and 1000 grain weight as compared with those noted for the control. The winter triticale grain yield components were most enhanced by the fertilization with straw and the mixture of birdsfoot trefoil with Italian ryegrass.

The after-effect of undersown intercrop and barley straw applied under potato was also observed for the winter triticale straw yield (Fig. 4). Fertilization of potato with undersown intercrop increased the successive crop yield by an average of 26.7% as compared with the control. Significantly highest straw yield was collected for winter triticale cultivated after potato fertilized with the mixture of birdsfoot trefoil with Italian ryegrass. Also in the reports by Siuta [18] and Małecka [8] organic fertilizers increased the successive crop straw yield. In the present research the objects which involved straw application under potato recorded an increase in the successive crop straw yield (by an average of 13.5%) as compared with the fertilization without straw from the object where triticale was cultivated after potato under which straw barley was not applied. The interaction of the factors researched shows that the highest winter triticale straw yield collected from the object fertilized under forecrop with the mixture of birdsfoot trefoil with Italian ryegrass and straw. The reports by Miczyński and Siwicki [9] showed that undersown intercrops ploughed in with a total of ½ of the dose of manure, as compared with the undersown crops only, clearly increase the successive crop straw yield. All that comes from the fact that a combined application of intercrop with manure or with straw provides soil with more biomass and macroelements made available to plants in crop rotation link.

As far as the qualitative yield evaluation is concerned, the cultivation of winter triticale depends more and more on the content and yield of total protein [2,15]. Potato cultivated after undersown intercrops and barley straw showed a favorable after-effect on the total protein yield of winter triticale grain and straw (Fig. 5). As for the objects on which winter triticale was cultivated after potato fertilized with undersown intercrops, the total protein yield of grain was 60.8% higher than that recorded for the control. The most favorable effect on the accumulation of total protein of winter triticale grain was noted for potato cultivated after the mixture of birdsfoot trefoil with Italian ryegrass. According to Krężel [6], Stopes et al. [19] and Zając et al. [23], the highest content of total protein was recorded for the grain of winter triticale cultivated in the second year after the fertilization with papilionaceous plants. In the present experiment, the total protein yield for grain of winter triticale cultivated after potato fertilized with birdsfoot trefoil or Italian ryegrass did not differ significantly from the total protein yield of grain of winter triticale cultivated after potato fertilized with manure. Fertilization with straw applied under winter triticale forecrop increased the total protein yield of grain significantly. Although barley straw applied as an organic fertilizer under potato, as the forecrop of winter triticale, did not increase significantly the content of total protein in grain, it did result in a significant increase in the grain yield. For that reason the total protein yield of grain, as a product content of protein and grain yield of winter triticale cultivated after potato fertilized with straw, was significantly higher. The interaction of the factors researched shows that significantly highest total protein yield of grain was obtained from the object from which the highest grain yield was collected, namely from winter triticale cultivated after potato fertilized with the mixture of birdsfoot trefoil with Italian ryegrass and straw.

CONCLUSIONS

1. The lowest weed infestation was recorded for the field of winter triticale fertilized under forecrop with the mixture of birdsfoot trefoil with Italian ryegrass.

2. Potato fertilization with undersown intercrops and barley straw showed a favorable after-effect on the grain yield, grain yield structure components, straw yield and total protein yield of winter triticale grain.

3. The highest grain yields, of the highest grain yield structure components values, straw yield, as well as the total protein yield of grain were obtained from winter triticale cultivated after potato under which the mixture of birdsfoot trefoil with Italian ryegrass and barley straw were ploughed in.

REFERENCES

1. Batalin M., Szałajda R., Urbanowski S., 1968. Wartość zielonego nawozu z poplonowych wsiewek roślin motylkowych [Value of green manure from some after-crop undersown papilionaceous plants]. Pam. Puł. 35, 37-51 [in Polish].

2. Berecz K., Kismanyoki T., Debreczni K., 2004. Studying the effect of organic matter recycling combined with mineral N fertilization in long - term field and model pot experiments. Arch. Agron. Soil Sci. 50 (1), 65-72.

3. Blecharczyk A., 1986. Wpływ zróżnicowanego nawożenia na plony roślin, zachwaszczenie i chemiczne właściwości gleby w monokulturze i zmianowaniu [Effect of a varied fertilization on crop yields, weed infestation and chemical properties of soil in monoculture and crop rotation]. Rocz. AR w Poznaniu, Rozpr. Nauk. 145 [in Polish].

4. Dzienia S., 1990. Wpływ międzyplonów na niektóre właściwości gleby i plonowanie roślin [Effect of intercrops on some soil properties and crop yielding]. Mat. konf. nauk. Międzyplony we współczesnym rolnictwie, AR Szczecin, 27-34 [in Polish].

5. Garwood T., Davies D., Hartley A., 1999. The effect of winter cover crops on yield of the following spring crops and nitrogen balance in a calcareous loam. J. Agric. Sci. 132, 1-11.

6. Krężel R., Mrówka M., Parylak D., Szumilak G., Hołyński E., 1988. Wpływ zmianowań specjalistycznych na plonowanie roślin i właściwości gleby lekkiej. Cz. I. Plonowanie i zachwaszczenie roślin [Effect of specialist crop rotations on crop yielding and light soil properties. Part I. Crop yielding and weed infestation]. Fragm. Agron. 4, 17-28 [in Polish].

7. Kuś J., 1997. Płodozmian w rolnictwie integrowanym [Crop rotation in integrated agriculture]. Acta Acad. Agric. Tech. Olst., Agricultura 64, 135-142 [in Polish].

8. Małecka I., 2002. Wpływ następczy roślin mulczujących i nawożenia azotem na plonowanie pszenżyta ozimego [After-effect of mulching plants and nitrogen fertilization on winter triticale yielding]. Folia Univ. Agric. Stetin., Agricultura 222, 75-80 [in Polish].

9. Miczyński J., Siwicki S., 1960. Międzyplony nawozowe w uprawie buraków cukrowych. Cz. II. Wsiewki międzyplonowe [Fertilization intercrops in the cultivation of sugar beets. Part II. Undersown intercrops]. Rocz. Nauk Roln. A 83(2), 311-348 [in Polish].

10. Nowak G., 1982. Przemiany roślinnej materii organicznej znakowanej izotopem C₁₄ w glebach intensywnie nawozonych [Transformations of organic matter of plants labeled with C₁₄ isotope in intensively-fertilized soils]. Zesz. Nauk. ART w Olsztynie, Rolnictwo 35, 3-57 [in Polish].

11. Parylak D., 1997. Zachwaszczenie pszenżyta ozimego w narastającej monokulturze [Weed infestation of winter triticale in increasing monoculture]. Zesz. Nauk. AR w Szczecinie, Rolnictwo 65, 299-305 [in Polish].

12. Pawłowski F., Woźniak A., 2000. Wpływ wsiewek poplonowych i nawożenia organicznego na plonowanie, zachwaszczenie i zdrowotność pszenżyta ozimego w monokulturze. Cz. II. Zachwaszczenie i zdrowotność [Effect of aftercrop undersown crops and organic fertilization on yielding, weed infestation and health status of winter triticale in monoculture. Part II. Weed infestation and heath status]. Zesz. Probl. Post. Nauk Roln. 470, 83-89 [in Polish].

13. Puła J., Łabza T., 2000. Następcze działanie nawożenia organicznego na jęczmień jary [After-effect of organic fertilization on spring barley]. Zesz. Probl. Post. Nauk Roln. 470, 91-98 [in Polish].

14. Richards I., Wallace P., Turner I., 1996. A comparison of six cover crop types in terms of nitrogen uptake and effect on response to nitrogen by a subsequent spring barley crop. J. Agric. Sci. 127, 441-449.

15. Rozbicki J., 1999. Zmienność plonu ziarna pszenżyta ozimego i zawartości białka w ziarnie w zależności od czynników agrotechnicznych i przebiegu pogody [Variation in winter triticale grain yield and protein content in grain depending on the agronomic factors and weather course]. Mat. konf. nauk. Środowiskowe i agrotechniczne uwarunkowania jakości płodów rolnych. Fundacja Rozwój SGGW Warszawa, 78-86 [in Polish].

16. Sadowski T., 1998. Następczy wpływ zróżnicowanego nawożenia okopowych na plonowanie jęczmienia jarego i owsa [After-effect of a varied fertilization of root crops on spring barley and oat yielding]. Acta Acad. Tech. Olst., Agricultura 66, 167-173 [in Polish].

17. Songin W., 1998. Międzyplony w rolnictwie proekologicznym [Intercrops in pro-ecological agriculture]. Post. Nauk Roln. 2, 43-51 [in Polish].

18. Siuta A., 1999. Wpływ nawożenia słomą i biomasą międzyplonu ścierniskowego na plonowanie zbóż i wybrane wskaźniki żyzności gleby [Effect of fertilization with straw and biomass of stubble intercrop on the yielding of cereals and selected soil fertility indicators]. Zesz. Probl. Post. Nauk Roln. 467, 245-251 [in Polish].

19. Stopes C., Milington S., Woolward L., 1996. Dry matter and nitrogen accumulation by three leguminous green manure species and the yield of a following wheat crop in an organic production system. Agric. Ecos. Envir. 57, 189-196.

20. Śnieg L., Piramowicz W., 1995. Wpływ sposobu nawożenia na plonowanie ziemniaka i zboża jarego w ogniwie zmianowania [Effect of fertilization method on potato and spring cereal yielding in crop rotation link]. Rocz. Nauk Roln. A 111(1-2), 127-134 [in Polish].

21. Witkowicz R., 1997. Wpływ następczy biomasy wsiewek poplonowych na plonowanie roślin zbożowych w dwóch kolejnych latach [After-effect of biomass of after-crop undersown crops on the yielding of cereal plants in two successive years]. Mat. konf. nauk. Nawozy roślinne w integrowanym systemie produkcji rolniczej, AR Kraków, 39-44 [in Polish].

22. Woźniak A., 2000. Wpływ wsiewek poplonowych i nawożenia organicznego na plonowanie, zachwaszczenie i zdrowotność pszenżyta ozimego w monokulturze. Cz. I. Plon ziarna [Effect of after-crop undersown crops and organic fertilization on yielding, weed infestation and health status of winter triticale in monoculture. Part I. Grain yield]. Zesz. Probl. Post. Nauk Roln. 470, 75-82 [in Polish].

23. Zając T., Kołodziejczyk M., Witkowicz R., 1998. Productivity of winter triticale in station after horse bean and spring triticale with undersown crops. Rocz. AR w Poznaniu, Rolnictwo 52, 93-99.