Fosforgödslingseffektivitet i långliggande bördighetsförsök

Rapid population growth and the fact that phosphorous is a limited resource implies that the question regarding an efficient use of phosphorus is of great importance, and consequently,that the phosphorous use efficiency should be as high as possible. The view on phosphorous use efficiency, and how t...

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Autor principal: Ehde, Lisa
Formato: L3
Lenguaje:sueco
Inglés
Publicado: SLU/Dept. of Soil and Environment 2012
Materias:
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author Ehde, Lisa
author_browse Ehde, Lisa
author_facet Ehde, Lisa
author_sort Ehde, Lisa
collection Epsilon Archive for Student Projects
description Rapid population growth and the fact that phosphorous is a limited resource implies that the question regarding an efficient use of phosphorus is of great importance, and consequently,that the phosphorous use efficiency should be as high as possible. The view on phosphorous use efficiency, and how this is calculated, has varied over time. This has had great implications on what type of research that has been conducted, which have resulted in an inconsistency between the academic’s view on the subject and recommendations received by farmers. The purpose of this paper is to calculate the phosphorus use efficiency in the Swedish long term fertility experiments. Calculations are made using different methods in order to evaluate which method is most suitable for calculating phosphorus use efficiency. Furthermore, the purpose is to determine at which P-AL you receive the highest efficiency for different soils and crops. Calculations made using the difference method consequently demonstrate lower phosphorus use efficiency than calculations made using the balance method. This implies that phosphorus is reversely fixed in the soil. The efficiency obtained using the difference method is strongly dependent on the yield in a references patch left unfertilized. Calculations on phosphorus use efficiency should therefore be made using the balance method. The highest efficiency achieved was 72 %, after correcting for an increase in P-AL. Nearly all of the sites had a phosphorus use efficiency over 25 %, which is commonly recognized as the upper limit. Yield in relation to P-AL differs greatly between different soils, differences that cannot be explained by simple soil parameters, such as content of clay and organic matter. According to Jodbruksverkets recommendations, replacement fertilizing should be done on soils graded as having phosphorus class III. The calculations show that the yield-effect of fertilizing decreases around P-AL 4, which corresponds to the lower regions of phosphorus class III. For some of the soils, this effect is observed at lower P-AL levels. There are significant differences between P-AL level required for a certain yield when different crops are compared. Calculations show that winter wheat is more tolerant to lower P-AL levels than spring barley and spring oilseeds. This is something that should be considered when planning phosphorus fertilization.
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spelling RepoSLU47892012-09-11T12:02:38Z Fosforgödslingseffektivitet i långliggande bördighetsförsök Efficiency of phosphorus fertilization in long-term soil fertility experiments Ehde, Lisa fosforgödslingseffektivitet bördighetsförsök balansmetod differensmetod fosfor Rapid population growth and the fact that phosphorous is a limited resource implies that the question regarding an efficient use of phosphorus is of great importance, and consequently,that the phosphorous use efficiency should be as high as possible. The view on phosphorous use efficiency, and how this is calculated, has varied over time. This has had great implications on what type of research that has been conducted, which have resulted in an inconsistency between the academic’s view on the subject and recommendations received by farmers. The purpose of this paper is to calculate the phosphorus use efficiency in the Swedish long term fertility experiments. Calculations are made using different methods in order to evaluate which method is most suitable for calculating phosphorus use efficiency. Furthermore, the purpose is to determine at which P-AL you receive the highest efficiency for different soils and crops. Calculations made using the difference method consequently demonstrate lower phosphorus use efficiency than calculations made using the balance method. This implies that phosphorus is reversely fixed in the soil. The efficiency obtained using the difference method is strongly dependent on the yield in a references patch left unfertilized. Calculations on phosphorus use efficiency should therefore be made using the balance method. The highest efficiency achieved was 72 %, after correcting for an increase in P-AL. Nearly all of the sites had a phosphorus use efficiency over 25 %, which is commonly recognized as the upper limit. Yield in relation to P-AL differs greatly between different soils, differences that cannot be explained by simple soil parameters, such as content of clay and organic matter. According to Jodbruksverkets recommendations, replacement fertilizing should be done on soils graded as having phosphorus class III. The calculations show that the yield-effect of fertilizing decreases around P-AL 4, which corresponds to the lower regions of phosphorus class III. For some of the soils, this effect is observed at lower P-AL levels. There are significant differences between P-AL level required for a certain yield when different crops are compared. Calculations show that winter wheat is more tolerant to lower P-AL levels than spring barley and spring oilseeds. This is something that should be considered when planning phosphorus fertilization. Den ökande befolkningens efterfrågan på mat och bristen på fosfor gör att effektiviteten i fosforgödslingen bör vara så hög som möjligt. Synen på fosforgödslingseffektivitet, och hur denna bör beräknas har sett olika ut under olika tidsperioder. Detta har fått implikationer för vilken forskning som bedrivits vilket i sin tur har lett till en diskripans mellan forskarvärldens syn på fosforgödslingseffektivitet och de praktiska rekommendationerna till lantbrukare. Syftet med detta arbete är att beräkna fosforgödslingseffektiviteten i långliggande bördighetsförsök på 12 platser i Sverige. Beräkningarna är gjorda med olika metoder för att utröna vilken metod som är lämpligast. Syftet med arbetet är även att utröna vilket P-AL som är optimalt för högst fosforgödslingseffektivitet för olika jordar och grödor. Beräkningar för långliggande bördighetsförsök i Sverige visar att effektiviteten av fosforgödslingen beräknat med differensmetoden är konsekvent lägre än beräknat med balansmetoden. Detta betyder att fosfor fixeras reversibelt i marken. Effektivitetsberäkningar bör göras med balansmetoden eftersom den effektivitet som erhålles med differensmetoden är starkt beroende av vad som sker i en ruta där ingen gödsling sker. Den högsta effektivitet som uppnåddes med balansmetoden, efter korrigering för ökning i P-AL, är 72 %. I princip samtliga beräkningar låg över de 25 % som tidigare ansetts vara maximal effektivitet. När det gäller skördens förhållande till P-AL är skillnaderna mellan olika jordar stor, och inget mönster finns som enkelt kan förklaras med markparametrar. Enligt Jordbruksverkets rekommendationer bör enbart ersättningsgödsling ske vid klass III. För flera av jordarna gäller att skördekurvan planar ut runt P-AL 4 vilket motsvarar en låg klass III, men för flera av jordarna sker utplaningen tidigare. Kurvorna visar även stor variation inom intervallet för klass III som går från P-AL 4,1-8,0. Det finns tydliga skillnader mellan vilket P-AL som krävs för att nå en viss skörd av olika grödor. Beräkningarna visar att höstvete klarar ett lägre P-AL än vårkorn och våroljeväxter som är allra känsligas något som bör beaktas vid gödslingsplanering. SLU/Dept. of Soil and Environment 2012 L3 swe eng https://stud.epsilon.slu.se/4789/
spellingShingle fosforgödslingseffektivitet
bördighetsförsök
balansmetod
differensmetod
fosfor
Ehde, Lisa
Fosforgödslingseffektivitet i långliggande bördighetsförsök
title Fosforgödslingseffektivitet i långliggande bördighetsförsök
title_full Fosforgödslingseffektivitet i långliggande bördighetsförsök
title_fullStr Fosforgödslingseffektivitet i långliggande bördighetsförsök
title_full_unstemmed Fosforgödslingseffektivitet i långliggande bördighetsförsök
title_short Fosforgödslingseffektivitet i långliggande bördighetsförsök
title_sort fosforgödslingseffektivitet i långliggande bördighetsförsök
topic fosforgödslingseffektivitet
bördighetsförsök
balansmetod
differensmetod
fosfor