Climate-friendly food

Climate change is without doubt one of the greatest challenges mankind has ever faced. This is not least due to the enormous consequences that climate change will have for the world’s ecosystems and for our living conditions. At the same time, climate change is a colossal political problem, in which the world’s democracies run the risk not being able to carry out the decisions that have to be made. The political and democratic problem builds on the very limited understanding that there is a connection between emissions of greenhouse gases, climate change and their impact on the living conditions of individual people. In reality, there is both a spatial and a temporal separation between emissions and effects. The world’s industrialised countries, which emit by far the largest amount of greenhouse gases, are in the first instance the least vulnerable to the effects of climate change. In addition, serious effects will first occur much later (decades to centuries) than the emissions. Therefore it can be very difficult to generate popular backing for serious initiatives against emissions of greenhouse gases. Agriculture and food production play an important role in this connection due to the importance of climate change for agriculture’s production basis and because it is one of the sectors emitting most greenhouse gases. For agriculture, the climate challenge is therefore double – it must both adapt to the changes and at the same time reduce its emissions of greenhouse gases

Organic farming and the challenges of climate change

Climate change is without question one of the largest challenges that humankind has ever faced. This is not the least due to the enormous consequences that climate change will have for ecosystems and human society. Unfortunately, climate change also poses a very difficult problem for politicians to deal with. The core of the problem affecting modern democracies is that most people experience very little relationship between greenhouse gas emissions, climate change and their everyday life. There is both a temporal and spatial separation between emissions and impacts of climate change. The industrialized countries, which currently emit most of the greenhouse gases, are in general the least vulnerable to climate change effects. Additionally, many of the detrimental effects of climate change will happen far later (decades to centuries) than the greenhouse gas emissions. It is therefore difficult to achieve substantial popular support for necessary and effective measures to mitigate climate change. Agriculture and food production plays an important role in this connection due to the importance of climate change for agriculture’s production basis and because of the large emissions of greenhouse gases from agriculture. For agriculture, the climate change challenge is therefore double – it must both adapt to the changes and at the same time reduce its emissions of greenhouse gases

Nitrate leaching from arable crop rotations in organic farming

Nitrate leaching from crop rotations for organic grain production were investigated in a field experiment on different soil types in Denmark from 1997 to 2002. Three experimental factors were included in the experiment in a factorial design: 1) proportion of grass-clover and pulses in the rotation, 2) cover crop (with and without), and 3) manure (with and without). Two four-course rotations were compared. They had one year of grass-clover as a green manure crop, either followed by spring wheat or by winter wheat. The nitrate leaching was measured using ceramic suction cells. The nitrate leaching did not differ between the rotations, as a change in leaching following the grass-clover was compensated by a reverse effect in the grain crops. Use of cover crops reduced N leaching by 23 to 38% at crop rotation level with the highest reduction on the coarse sandy soil. Simulation of N leaching using the FASSET model showed that a practice of using part of the summer period in the grass-clover as a bare fallow to control couch grass could increase leaching substantially, in particular on the sandy soil

Nitrate leaching from arable crop rotations in organic farming

The crop rotation is a crucial and integral part of organic farming systems. It must be designed to maintain and exploit soil fertility, and to minimise the impacts on environment, e.g. through nitrate leaching. Crop rotations in organic farming typically include legume crops to provide nitrogen fixation and improve soil fertility. Catch crops are also commonly used, if demands for soil tillage to control perennial weeds allow. This paper presents results on nitrate leaching from a field experiment with comparison of three different crop rotations with and without catch crops designed for organic farming

European Integration: Some stylised facts

The European economic integration has been an ongoing process for nearly a half century. This article discuss initially the concept of integration and then gives an overall assessment of the development of integration on various areas. Evidence points to a remarkable process towards monetary integration especially in the last decades. The significant increase of the intra-EU trade also points to a more integrated Europe especially since the establishing of the internal market. However, the integration seems to have less impact on other areas e.g. synchronisation of the business cycles between Member States and convergence of living standards. Prospects for the future development of integration is also discussed in the article.

Cereal yield and quality as affected by N availability in organic and conventional crop rotations in Denmark: a combined modeling and experimental approach

The effects of nitrogen (N) availability related to fertilizer type, catch crop management, and rotation composition on cereal yield and grain N were investigated in four organic and one conventional cropping systems in Denmark using the FASSET model. The four-year rotation studied was: spring barley–(faba bean or grass-clover)– potato–winter wheat. Experiments were done at three locations representative of the different soil types and climatic conditions in Denmark. The three organic systems that included faba bean as the N fixing crop comprised a system with manure (stored pig slurry) and undersowing catch crops (OF+C+M), a system with manure but without undersowing catch crops (OF−C + M), and a system without manure and with catch crops (OF + C−M). A grass-clover green manure was used asNfixing crop in the other organic system with catch crops (OG+C+M). Cuttings of grass-clover were removed from the plots and an equivalent amount of total-N in pig slurry was applied to the cropping system. The conventional rotation included mineral fertilizer and catch crops (CF+C+F), although only non-legume catch crops were used. Measurements of cereal dry matter (DM) at harvest and of grain N contents were done in all plots. On average the FASSET model was able to predict the yield and grain N of cereals with a reasonable accuracy for the range of cropping systems and soil types studied, having a particularly good performance on winter wheat. Cereal yields were better on the more loamy soil. DM yield and grain N content were mainly influenced by the type and amount of fertilizer-N at all three locations. Although a catch crop benefit in terms of yield and grain N was observed in most of the cases, a limited N availability affected the cereal production in the four organic systems. Scenario analyses conducted with the FASSET model indicated the possibility of increasing N fertilization without significantly affecting N leaching if there is an adequate catch crop management. This would also improve yields of cereal production of organic farming in Denmark

High Root Biomass FOR cereal crops increases carbon sequestration in organic Arable systems

In agroecosystems, soil organic carbon (C) inputs come from applied manures, plant roots and retained shoot residues. Several reasons, associated with root measurements, limit current knowledge on root C input.This study aimed at evaluating root responses to nutrient management and fertility building measures (e.g. catch crops). We made use of one inorganic fertilizer-based and two organic systems in an 11-year-old field experiment on sandy loam soil. At anthesis, soil cores (5 cm dia.) were sampled from 0-30 cm depth within and between rows of winter wheat and spring barley. Roots were separated from soil and washed with tap water, the dry matter (DM) biomass was determined. Dry matter biomass was also measured in shoots.The spring barley root DM was at least 30% higher in the organic compared to the inorganic fertilizer-based system. The organic system that included catch crops had 17% higher spring barley root DM than where catch crops were absent. In the inorganic fertilizer-based system, the biomass shoot-to-root ratio for spring barley was double that in the comparable organic system. High root DM biomass in organic compared to the inorganic fertilizer-based systems, implies higher C sequestration in the former, especially considering the slow decomposition rate of root residues

Sommer i sædskifteforsøget

Efter en uge med meget tørt og blæsende vejr var det skønt at få lidt regn. På sandjorden på Jyndevad kørte vandingen for fuld kraft og selv på den lerblandede sandjord på Foulum var nogle af de kraftigere afgrøder begyndt at vise tegn på vandmangel. Det er ganske tydeligt, at en gødet afgrøde efter en god forfrugt bruger mere vand end en spinkel ugødet afgrøde. Såtidspunkt i vinterhvede De sidste to år har vi forsøgt os med tidlig såning af vintersæden på Jyndevad og Foulum. På Jyndevad dyrker vi vinterrug, og her klarer en tidlig såning sig fint. Rugen vokser godt til i efteråret og kan med lidt hjælp af ukrudtsstriglen sagtens konkurrere med ukrudtet. På Foulum dyrker vi vinterhvede, som er langt mindre konkurrencedygtig mod ukrudtet. Især vokser vinterhvede betydeligt langsommere om efteråret, og den yder kun ringe konkurrence mod ukrudtet. I de første fire år blev vinterhveden på Foulum sået omkring 1 oktober. Det gav en lille ukrudtsfremspiring og små ukrudtsplanter, som forholdsvis let kunne klares med harvninger om foråret. Den sene såning gav dog en svagt etableret hvede, og vi har derfor i de seneste to år forsøgt med såning af vinterhvede i begyndelsen af september. Vi valgte samtidigt at fordoble rækkeafstanden, så vi kunne bruge radrenseren til at kontrollere ukrudtet. Det er ikke gået så godt. Hveden stod betydeligt bedre i efteråret, men er ikke væsentligt kraftigere her i juni end den var tidligere. Dette skyldes nok en generel mangel på kvælstof. Til gengæld har vi nu en betydeligt kraftigere bestand af ukrudt, især kamille, hvilket også bliver at mærke på udbyttet. Dette til trods for en meget intensiv ukrudtsbekæmpelse med to harvninger og en radrensning i efteråret, og den samme behandling i foråret. Lupin på sand- og lerjord I år dyrker vi lupin sammen med vårbyg, på Jyndevad dog også i blanding med hestebønner. Dette er gjort for at øge udbyttestabiliteten i bælgsædsafgrøden samt for at øge konkurrenceevnen mod ukrudt. Sidste år var der store udbyttetab i lupin på Jyndevad som følge af gråskimmel, og på Holeby og Flakkebjerg var lupinen meget beskidt med ukrudt, på Flakkebjerg især kvik. Det skyldtes en dårligere etablering på lerjordene og at lupin smider bladene sidst på sæsonen. Herved bliver afgrøden meget åben og inviterer ligefrem kvikken til at stikke hovedet frem. I år står lupinen betydeligt bedre på Jyndevad og Foulum sammenlignet med Flakkebjerg og Holeby. Det hænger formentlig sammen med såvel jord- som klimaforhold. Det virker som om lupin er noget følsom over for dårlig jordstruktur i etableringsfasen. Derimod er lupin tilsyneladende nogenlunde ligeglad med forhistorien. Det samme er ikke tilfældet med hestebønner, som dyrkes i blandingen på Jyndevad. Her står hestebønnerne 10-15 cm lavere i de parceller, hvor der ikke har været givet gødning i de foregående år. Der gødes ikke i selve bælgsædsafgrøden

Gunstige effekter af efterafgrøder i sædskifteforsøget

Nu er sommeren snart ved at være gået. Det blev en sommer med meget variabelt vejr. På alle forsøgssteder er der kommet passende med regn til at etableret udlægget godt i sædskifteforsøget. Det varme vejr har dog kostet lidt ekstra vanding i år på sandjorden på Jyndevad. Nu håber vi bare på, at vejret også kan holde tørt i høsten. Etablering af udlæg Der har tidligere især været problemer med at etablere et godt kløverudlæg på Foulum. Det skyldes ikke alene konkurrence fra den gødede dæksæd, men også at der forekom meget ukrudt, der også konkurrerede med kløveren i bunden af afgrøden. Ukrudtet har tidligere været fremmet af at gødningen er nedharvet i såbedet. Desuden blev der ikke er gennemført ukrudtsbekæmpelse, fordi udlægget er udsået omtrent samtidigt med dæksæden. I år har vi valgt at nedfælde gyllen, og samtidigt er der gennemført både en blindstrigling og en efterfølgende ukrudtsharvning. Det har resulteret i betydeligt mindre ukrudt end i tidligere år. På Foulum er halvdelen af kløvergræs-udlægget udsået sammen med kornet. Både græs og kløver spirede pænt frem i kornrækkerne, men kun noget af græsset og enkelte rødkløver-planter har overlevet ukrudtsharvningen. Den resterende halvdel af udlægget blev udsået efter ukrudtsharvningen, og en regnbyge dagen efter sikrede en god fremspiring. Efterafgrøder Der begynder nu at være gode effekter af efterafgrøder i de fleste af sædskifterne. Det er bl.a. tilfældet i sædskiftet uden kløvergræs, hvor efterafgrøden af hvidkløver har givet et rigtigt godt grundlag for vårbyggen. De gode effekter af efterafgrøderne skyldes nok både en effekt på afgrødernes kvælstofforsyning, men også gunstige effekter på andre næringsstoffer og på jordstrukturen. At efterafgrøder også kan spille en rolle for afgrødernes kaliumforsyning kan ses på Jyndevad. Her er der nærmest misvækst af kløver i kløvergræsmarker uden gødningstilførsel, men kun i systemerne uden efterafgrøder. I systemerne med efterafgrøder er der tydelige symptomer på kaliummangel, men kløveren gror dog alligevel nogenlunde fornuftigt. På både Foulum og Flakkebjerg dyrkes i år lupin. Begge steder vokser denne afgrøde tydeligt bedst, hvor der er efterafgrøder i systemet. Dette skyldes formentlig en gunstig virkning af efterafgrøderne på jordstrukturen, som fremmer rodudvikling og dannelse de rodknolde, der er grundlaget for kvælstoffikseringen. Der er nogen ukrudt i lupinen på begge forsøgssteder. Værst står det til på Flakkebjerg i parceller med efterafgrøder, hvor der ikke blev foretaget ukrudtsbekæmpelse. På Foulum er der lidt mindre ukrudt i parceller med efterafgrøder, fordi lupinerne her har groet lidt bedre til og fordi der her er foretaget ukrudtsbekæmpelse

Simple soil carbon model for use in the HighCrop decision model

The soil carbon turnover model used in the HighCrop decision support model is described