Crop rotations sustain cereal yields under a changing climate

Agriculture is facing the complex challenge of satisfying increasing food demands, despite the current and projected negative impacts of climate change on yields. Increasing crop diversity at a national scale has been suggested as an adaptive measure to better cope with negative climate impacts such as increasing temperatures and drought, but there is little evidence to support this hypothesis at the field scale. Using seven long-term experiments across a wide latitudinal gradient in Europe, we showed that growing multiple crop species in a rotation always provided higher yields for both winter and spring cereals (average +860 and +390 kg ha−1 per year, respectively) compared with a continuous monoculture. In particular, yield gains in diverse rotations were higher in years with high temperatures and scant precipitations, i.e. conditions expected to become more frequent in the future, rendering up to c. 1000 kg ha−1 per year compared to monocultures. Winter cereals yielded more in diverse rotations immediately after initiation of the experiment and kept this advantage constant over time. For spring cereals, the yield gain increased over time since diversification adoption, arriving to a yearly surplus of c. 500 kg ha−1 after 50-60 years with still no sign of plateauing. Diversified rotations emerge as a promising way to adapt temperate cropping systems and contribute to food security under a changing climate. However, novel policies need to be implemented and investments made to give means and opportunities for farmers to adopt diversified crop rotations

The phenology of winter rye in Poland: an analysis of long-term experimental data

The study of the phenology of crops, although quite popular, has limitations, mainly because of frequent changes to crop varieties and management practices. Here, we present data on the phenology and yield of winter rye in western Poland collected between 1957 and 2012 from a long-term field experiment. Data were examined for trends through time and compared to climatological factors using regression analysis. Both annual air temperature and precipitation increased during the study period, equivalent to 2 °C and 186 mm, respectively, over the 52-year period for which met data were available. We detected significant delays in sowing date and recently in emergence, but significant advances were apparent in full flowering date equivalent to 4 days/decade. Yield and plant density experienced a step like change in 1986; yield increasing by ca. 70 % and plant density increasing by ca. 50 %, almost coinciding with a similar change in annual mean temperature, but most likely caused by a changed seed rate and use of herbicides. Future climate change is expected to have a greater impact on this crop, but farmers may be able to adapt to these changes by modifying water regimes, using new machinery and sowing new rye varieties

Crop rotational diversity can mitigate climate-induced grain yield losses

Diversified crop rotations have been suggested to reduce grain yield losses from the adverse climatic conditions increasingly common under climate change. Nevertheless, the potential for climate change adaptation of different crop rotational diversity (CRD) remains undetermined. We quantified how climatic conditions affect small grain and maize yields under different CRDs in 32 long-term (10-63 years) field experiments across Europe and North America. Species-diverse and functionally rich rotations more than compensated yield losses from anomalous warm conditions, long and warm dry spells, as well as from anomalous wet (for small grains) or dry (for maize) conditions. Adding a single functional group or crop species to monocultures counteracted yield losses from substantial changes in climatic conditions. The benefits of a further increase in CRD are comparable with those of improved climatic conditions. For instance, the maize yield benefits of adding three crop species to monocultures under detrimental climatic conditions exceeded the average yield of monocultures by up to 553 kg/ha under non-detrimental climatic conditions. Increased crop functional richness improved yields under high temperature, irrespective of precipitation. Conversely, yield benefits peaked at between two and four crop species in the rotation, depending on climatic conditions and crop, and declined at higher species diversity. Thus, crop species diversity could be adjusted to maximize yield benefits. Diversifying rotations with functionally distinct crops is an adaptation of cropping systems to global warming and changes in precipitation.</p

Increasing crop rotational diversity can enhance cereal yields

9 Pág.Diversifying agriculture by rotating a greater number of crop species in sequence is a promising practice to reduce negative impacts of crop production on the environment and maintain yields. However, it is unclear to what extent cereal yields change with crop rotation diversity and external nitrogen fertilization level over time, and which functional groups of crops provide the most yield benefit. Here, using grain yield data of small grain cereals and maize from 32 long-term (10–63 years) experiments across Europe and North America, we show that crop rotational diversity, measured as crop species diversity and functional richness, enhanced grain yields. This yield benefit increased over time. Only the yields of winter-sown small grain cereals showed a decline at the highest level of species diversity. Diversification was beneficial to all cereals with a low external nitrogen input, particularly maize, enabling a lower dependence on nitrogen fertilisers and ultimately reducing greenhouse gas emissions and nitrogen pollution. The results suggest that increasing crop functional richness rather than species diversity can be a strategy for supporting grain yields across many environments.G.V., R.B. and S.H. acknowledge FORMAS grants 2018-02872 and 2018-02321. TMB acknowledges USDA AFRI grant 2017-67013-26254. LTEs managed by SRUC were supported by the Scottish Government RESAS Strategic Research Programme under project D3-, Healthy Soils for a Green Recovery. Swedish LTEs were funded by the Swedish University of Agricultural Sciences (SLU). We thank the Lawes Agricultural Trust and Rothamsted Research for data from the e-RA database. The Rothamsted Long-term Experiments National Capability (LTE-NC) was supported by the UK BBSRC (Biotechnology and Biological Sciences Research Council, BBS/E/C/000J0300) and the Lawes Agricultural Trust. The Woodslee site was supported by the Agro-Ecosystem Resilience Program (Agriculture & Agri-Food Canada) and field management provided by field crews over 6 decades is appreciated. La Canaleja LTE (Spain) was supported by RTA2017-00006-C03-01 project (Ministry of Science and Innovation. El Encín LTEs were supported by Spanish Ministry of Economy and Competitiveness funds (projects AGL2002-04186-C03-01.03, AGL2007-65698-C03-01.03, AGL2012-39929-C03-01 of which L. Navarrete was the P.I). R.A., A.G.D. and E.H.P. are also grateful to all members of the Weed Science Group from El Encín Experimental Station for their technical assistance in managing the experiments. The Brody/Poznan University of Life Sciences long-term experiments were funded by the Polish Ministry of Education and Science. We acknowledge the E-Obs dataset from the EU-FP6 project UERRA (http://www.uerra.eu) and the Copernicus Climate Change Service, and the data providers in the ECA&D project (https://www.ecad.eu/).Peer reviewe

Effect of the place in the crop rotation and fertilization on weediness of winter rye and soil

Исследования по влиянию севооборота и удобрения на засорение поля проводились в трех очередных годах 1980-1982 в рамках статического опыта заложенного в 1957 г. в опытной станции Броды. Озимая рожь возделывалась в монокультуре и в 7-летнем севообороте. В исследованиях были приняты следующие удобрительные варианты: контроль без удобрения, стойловый навоз, стойловый навоз + NРK, NРK + Ca, NРK, NK, PK, N, Р и K. Возделывание озимой ржи в монокультуре приводило к росту численности и массы сорняков в поле и к повышению массы диаспор сорняков в почве. Севооборот и удобрение приводили к существенным изменениям в видовом составе сорняков в озимой ржи и диаспор сорняков в почве. Под монокультурой повышалось участие таких сорняков, как Apera spicaventi, Veronica sp., Vicia sp., Arenaria serphyllifolia, Centaurea cyanus u Lithospermum arvense.Investigations on the effect of crop rotation and fertilization on weediness of winter rye were carried out in the subsequent years 1980-1982 within the framework of a static experiment established in 1957 at the Agricultural Experiment Station'Brody. Winter rye was cultivated in monoculture and in the 7-year crop rotation. The experiment comprised the following fertilizing treatments: no fertilization (control), farmyard manure, farmyard manure + NPK, NPK + CA, NPK, NP NK, N, P and K. The winter rye monoculture caused a growth of the number and mass of weeds in the field and a increase of the mass of weed diaspores in soil. The applied crop rotation and fertilization led to significant changes in the species composition of weeds on the winter rye field and of diaspores in soil. The share of such weed species, as Apera spica-venti, Veronica sp., Vicia sp., Arenaria serphyllifolia, Centaurea cyanus and Lithospermum arvense increased in the monoculture

Effect of crop sequence and fertilization on yield and chemical composition of potato tubers cv. Sante

Badania przeprowadzono w latach 2000-2006 w Stacji Badawczej Brody (52o26’ N; 16o18’ E), należącej do Uniwersytetu Przyrodniczego w Poznaniu, na obiektach wieloletniego doświadczenia założonego w 1957 roku. Ziemniak uprawiano w 7-po-lowym zmianowaniu oraz w monokulturze ciągłej, w warunkach zróżnicowanego nawożenia (kontrola bez nawożenia, obornik, obornik + NPK, NPK). Plon bulw ziemniaka uprawianego w monokulturze był o 50,8% mniejszy niż w zmianowaniu. Największy plon bulw uzyskano po łącznym nawożeniu obornikiem z NPK; zastosowanie samego obornika bądź nawożenia wyłącznie mineralnego obniżyło plon bulw odpowiednio o 14,6 i 22,8%. Obornik, zwłaszcza stosowany łącznie z NPK, wpłynął korzystnie na zawartość N, P, K i Mg w bulwach w porównaniu z nawożeniem wyłącznie mineralnym, obniżał natomiast zawartość suchej masy, skrobi oraz wapnia.The research was conducted during the years 2000-2006 on the base of a long-term study established in 1957, at the Experimental Station Brody (52o26’ N; 16o18’ E) belonging to the University of Life Sciences in Poznań. Potato was grown continuously and in seven-course crop rotation at four levels of fertilization: control without fertilization, farmyard manure, farmyard manure + NPK, NPK. In continuous cropping the mean yield of potato was lowered by 50.8% as compared with crop rotation for 7-year period. The highest yield of potato tubers was obtained after combined treatment with farmyard manure and NPK. Fertilization only with farmyard manure or NPK decreased the tuber yield by 14.6 and 22.8 per cent, respectively. Combined farmyard manure and NPK treatment had a favourite effect on N, P, K and Mg content in tubers compared to NPK plots, but decreased dry matter, Ca and starch contents

Wpływ systemu następstwa roślin oraz nawożenia na odczyn gleby w doświadczeniu wieloletnim

Field experiments were conducted in 1995 - 1996 at Brody Experimental Station of Poznań Agricultural University in order to investigate the influence of long-term (over 35 years) diferentiated fertilization on soil properties. The use of farmyard manure stabilized the soil pH while under mineral fertilization decreasing in soil pH was observed. Long-term liming of soil led to a growth of the phosphorus, potassium, organic carbon and total nitrogen contents in soil

Possibilities of reduced tillage for spring barley

Celem badań było określenie wpływu trzech sposobów uprawy roli: tradycyjnego, uproszczonego i siewu bezpośredniego na tle zróżnicowanego nawożenia organicznego, które stanowił: międzyplon ścierniskowy, słoma i ściernisko (obiekt kontrolny) oraz trzech dawek nawożenia azotem (0, 50 i 100 kg·ha-1) na plonowanie jęczmienia jarego. Jęczmień jary plonował na wyższym poziomie w uprawie tradycyjnej aniżeli w uprawie uproszczonej i siewie bezpośrednim. Najwyższy plon ziarna jęczmienia jarego uzyskano po międzyplonie ścierniskowym z udziałem rośliny strączkowej, natomiast pozostawienie słomy powodowało istotne obniżenie plonu ziarna we wszystkich systemach uprawy roli. Jęczmień jary uprawiany bez nawożenia azotem w stanowisku po międzyplonie ścierniskowym plonował na wyższym poziomie aniżeli po ściernisku lub słomie po nawożeniu dawką 50 kg N·ha-1. Wprowadzenie do uprawy międzyplonu ścierniskowego z udziałem rośliny strączkowej pozwala uzyskiwać wysokie plony roślin następczych przy stosowaniu małych dawek azotu oraz ograniczać ujemną reakcję roślin na uproszczone systemy uprawy roli.The objective of this study was to determine the effect of varied organic fertilisation of stubble intercrop, straw and stubble (the control) and three nitrogen fertilizer doses (0, 50 and 100 kg·ha-1) with three tillage methods: traditional, simplified and direct sowing, on spring barley yield. Spring barley yielded higher when exposed to traditional tillage than to simplified tillage and direct sowing. The highest spring barley grain yield was recorded after stubble intercrop when a legume participated, while leaving straw significantly decreased the grain yield in all the tillage systems. Spring barley grown without nitrogen fertilisation after stubble intercrop yielded higher than barley after stubble or straw following the fertilisation with the dose of 50 kg·ha-1 of N. Introducing a stubble intercrop with a participation of a legume allows for high yields of successive crops with low N fertilizer doses and for reducing a negative response of crops to simplified tillage systems

Zachwaszczenie jeczmienia jarego w zaleznosci od systemow uprawy roli i roslin mulczujacych

Doświadczenie polowe przeprowadzono w latach 2000-2002 w Stacji Doświadczalnej Brody należącej do Akademii Rolniczej w Poznaniu. Czynnikami badawczymi były cztery systemy uprawy roli (tradycyjny, orka wiosenna, uproszczony przy użyciu kultywatora ścierniskowego, siew bezpośredni) i cztery rodzaje roślin mulczujących (dwa międzyplony ścierniskowe: gorczyca biała i mieszanka owsa z grochem, słoma pszenicy ozimej i obiekt kontrolny bez mulczu - ściernisko). W doświadczeniu oznaczono liczbę i biomasę chwastów oraz skład gatunkowy na powierzchni 1 m². Niezależnie od rośliny mulczującej ogólna liczba chwastów zwiększała się z 40 szt.·m⁻² w siewie bezpośrednim do 399 szt.·m⁻² w uprawie tradycyjnej. Międzyplony ścierniskowe i słoma we wszystkich systemach uprawy roli istotnie obniżały ogólną liczbę chwastów w porównaniu do obiektu bez rośliny mulczującej. Czynniki badawcze w mniejszym stopniu oddziaływały na biomasę chwastów aniżeli na liczbę chwastów. Dominującymi gatunkami chwastów we wszystkich kombinacjach badawczych były Viola arvensis, Capsella bursa-pastoris, Polygonum spp. i Chenopodium album. W uprawie tradycyjnej odnotowano wzrost udziału Viola arvensis i Chenopodium album w porównaniu do siewu bezpośredniego. W systemie siewu bezpośredniego nastąpił wzrost liczby chwastów takich jak Taraxacum officinale, Plantago major, Cirsium arvense, Poa annua, Apera spica-venti i Agropyron repens. Międzyplony ścierniskowe oraz mulcz słomy zmniejszały ogólną liczbę chwastów, poprzez ograniczenie występowania przede wszystkim Capsella bursa-pastoris, Geranium pusillum i Brassica napus.Field studies were conducted in the years 2000-2002 at Research Station Brody of the Agricultural University of Poznań. Treatments included four tillage systems (conventional tillage, spring mouldboard ploughing, reduced tillage with shallow stubble cultivator, no-tillage) with four mulching practices (two cover crops: Sinapis alba and Avena sativa-Pisum sativum mixture, winter wheat straw mulch, and no mulch). Weed species density and aboveground fresh weight were determined in 1 m² areas of each plot. Total weed density increased from 40 plants·m⁻² in no-tillage to 399 plants·m⁻² for the conventional tillage over mulch. Cover crops and straw mulch in four tillage systems significantly decreased total weed populations as compared to with the treatment without mulch. The treatments had lower effects on weed biomass than on weed density. The dominant weed species in all treatments were Viola arvensis, Capsella bursa-pastoris, Polygonum spp. and Chenopodium album. Viola arvensis and Chenopodium album density increased in conventional tillage as compared to no-tillage system. Species that increased in density in no-tillage system were Taraxacum officinale, Plantago major, Cirsium arvense, Poa annua, Apera spica-venti and Agropyron repens. Weed density reduction by cover crops and straw mulch in this study was primarily due to the reductions in Capsella bursa-pastoris, Geranium pusillum i Brassica napus