Dinitrogen fixation and residue nitrogen of different managed legumes and nitrogen uptake of subsequent winter wheat

Transcription

1 Dinitrogn fixtion n rsiu nitrogn of iffrnt mng lgums n nitrogn uptk of susqunt wintr wht R. Logs 1, A. Ksk 2 n F. Tu 2 1 Dprtmnt of Orgni Frming, Univrsity of Kil, 2 Dprtmnt of Grss n Forg Sin, Univrsity of Kil, Holzkopplwg 2, Kil, Grmny Summry Fix nitrogn umult y lgums is th min nitrogn sour for orgni frming systms. Knowlg out th mount of fix nitrogn, its pthwys into forg yil, rop rsius, soil-n n yil formtion of th following rop is n for signing rop rottions. Two fil xprimnts wr onut in Northrn Grmny with iffrntly mng (ut, mulh) lgums (r lovr, lflf, whit lovr) in pur stns n vrious mixturs with two ompnion grsss (Lolium multiflorum, Lolium prnn) hv n grown to trmin N 2 -fixtion, rsiu nitrogn n N-uptk of susqunt rops. Cropp grss/lgum rh highr N 2 -fixtion thn mulh. Whil grn mnur grss/lgum lft up to 28 kg h -1 of N in mulh, stul n roots on th fil, most ropp grss/lgum mixturs lft lss thn 11 kg N h -1 in rop rsius. Pur lgum swrs or lgum rih mixturs show highr N 2 -fixtion thn grss rih mixturs. N-uptk in lt utumn n t mturity of th susqunt wht ws strongly orrlt to th lgum ontnt in DM-yil. Introution Symiotilly fix nitrogn umult y lgums is th min nitrogn sour for orgni frming systms. In rop rottions forg lgums lik r lovr (Trifolium prtns), lflf (Migo stiv) n whit lovr (Trifolium rpns) show highr nitrogn fixtion thn grin lgums lik ps or f ns (Lru n Pttrson, 1981; Hgmir, 1986). Forg lgums r slf suffiint with nitrogn, thir N 2 -fixtion n ovr th nitrogn mn of svrl susqunt non-n 2 -fixing rops (MBrtny, 1981; Bowly t l., 1984). In Northrn Grmny r lovr mix with prnnil rygrss (Lolium prnn) or Itlin rygrss (Lolium multiflorum) is th min forg lgum grown in rop rottions. R lovr/grss is usully ut 3 tims for silg for wintr forg or grown s grn mnur on st si ln with th possiility to riv EU-susiis. Grzing ly lovr/grss-mixturs is slom, us Grmn frms usully hv high proportion of prmnnt pstur n th vrg stoking rt on Grmn orgni frms is low. As th EU os not py susiis for growing grss/lovr for forg us n th susiis for st si ln r low, spilly rl frmrs try to uil up rop rottions whr fix N y lgums is us ffiint to kp th prntg grss/lovr in th rop rottion s low s possil. Thr r two pthwys for th nitrogn fix y forg lgums to mt th N-mn of th following rops: - irt y mulh, stul n roots, - inirt y slurry or stl mnur ftr fing th onsrv nsil lgum hrg.

2 For signing rop rottions with high nitrogn us ffiiny, knowlg out th mount of fix nitrogn, its pthwys into forg yil, rop rsius, soil-n n yil formtion of th susqunt rops for iffrnt mng lgums is nssry. For this rson th following fil xprimnts hv n sign. Mtril n mthos Th two fil xprimnts wr onut on sny, lomy misol (14% ly) t th xprimntl sttion Hohnshuln nr Kil in Northrn Grmny (9 37'E, 54 21'N). Rsults r prsnt minly from th growing ssons of 1994 to Annul pripittion ws 95, 638, 522, 685 n 987 mm in 1994, 1995, 1996, 1997 n 1998 rsptivly. Th following nnul mn tmprturs hv n ror: 9,2 C (1994): 8,7 C (1995), 7,1 C (1996) 8,8 C (1997) n 8,8 C (1998). Exprimnt 1 Th im of xprimnt 1 ws to trmin th fft of forg lgum spis, s mixtur n mngmnt on yil, N 2 -fixtion, rsiu nitrogn n pring rop vlu of lgum/grss mixturs. Th xprimnt inlus th following ftors: 1. Mngmnt (form of us) 4 x ropp (forg proution) 2 x mulh (grn mnur) 2. Lgum spis whit lovr (v. Milknov ) r lovr (v. Mro ) lflf (v. Plnt ) 3. S mixtur pur sown lgum whit lovr: 6 kg h -1, r lovr: 12 kg h -1 or lflf: 24 kg h -1 lgum/grss mixtur whit lovr: 4 kg h -1, r lovr: 8 kg h -1 or lflf: 16 kg h -1 in mixtur with prnnil rygrss: 2 kg h -1 (v. Mnt ) pur sown grss prnnil rygrss: 3 kg h -1 (v. Mnt ) s rfrn rop for msurmnt of N 2 -fixtion All swrs hv n stlish in mi August in h of th following yrs: 1996, 1997 n 1998 in opn sowing in four rplitions. Plot siz ws 9 m x 1 m. No frtilisr ws ppli, ll swrs wr hn w. Aftr on growing sson th swrs wr plough without stul rking t two iffrnt ts (n of Sptmr/n of Otor). Wintr wht (v. Orstis ) ws sown immitly ftrwrs with rt of 29 ss m -2 (n of Sptmr) or 35 ss m -2 (n of Otor). Exprimnt 2 Th im of xprimnt 2 ws to trmin th impt of ompnion grss spis, s rt n mngmnt on yil, N 2 -fixtion n pring rop vlu of r lovr/grss. Th xprimnt inlu th following ftors: 1. S mixtur: 1 % r lovr (v. Mro ) 12 kg h % r lovr + 33 % grss 8 kg h kg h % r lovr + 67 % grss 4 kg h kg h -1 1% grss 3 kg h -1

3 2. Compnion grss: Itlin rygrss (v. Mlmi ) (rprsnting vry high omptitiv ompnion grss) prnnil rygrss (v. Mnt ) (with lowr omptitivnss thn Itlin rygrss) 3. Sing t /Durtion of ly / Mngmnt (form of us) : ugust 1993 / 2-yrs / 1994/95: 4/4 uts (forg proution) ugust 1994 / 1-yr / 1995: 4 uts (forg proution) ugust 1994 / 1-yr / 1995: 2 mulhing uts (grn mnur) Th swrs hv n stlish in h yrs in opn sowing in four rplitions. Plot siz ws 9 m x 12 m. No frtilisr ws ppli, ll swrs wr hn w. Aftr on/two growing sson(s) swrs wr plough without stul rking t two iffrnt ts (n of Sptmr/n of Otor 1995). Wintr wht (v. Orstis ) ws sown immitly ftrwrs with rt of 29 ss m -2 (n of Sptmr) or 35 ss m -2 (n of Otor). Dtrmin prmtrs In oth xprimnts th following prmtrs hv n trmin: rop yil n lovr ontnt of h ut, orgni mttr of stul, roots (pth - 3 m) n mulh for ploughing, forg qulity prmtrs of hrg, N-ontnt of ll plnt mtril, CCl 2 -xtrtl minrl n orgnil soil-n (pth - 9 m) for ploughing, N 2 -fixtion (Totl-N-iffrn mtho (Hry n Holstn, 1975) s on th N- mounts in hrvst plnt mtril, rop rsius n th CCl 2 -xtrtl soil-n frtions with th pur grss swrs s rfrn rops), grin yil, totl ry mttr for wintr in utumn n t mturity of wintr wht, N-ontnt/ru protin onntrtion in wht vgttiv tissu mtril n grin. Rsults n isussion In xprimnt 1 th iffrnt omintions of th ftors lgum spis, s mixtur n mngmnt show highly signifint ffts on proution of ry mttr, hrvst N, N in rop rsius n N 2 -fixtion of swrs with forg lgums. Also grin yil of th susqunt wintr wht ws influn y ths ftors. Th hosn ftors h no fft on grin protin ontnt of wintr wht. Figur 1 shows th fft of iffrnt omintions of lgum spis, s mixtur n mngmnt on DM-proution, hrvst N-yil n th N-mount in rop rsius. Unr oth mngril systms grss/lgum-mixturs show highr proution of ry mttr thn pur lgum stns. In ll mixturs n mngril systms whit lovr rh signifintly lowr yils thn lflf or r lovr. Unr oth mngril systms th r lovr/grss mixtur hiv th highst ry mttr proution. Whil in th grn mnur systm th whol plnt mtril ftr mulhing rmin on th fil, t lst 25 kg N h -1 wr hrvst from h of th ropp lgum stns. Th swrs with whit lovr show signifintly lowr N-yils thn th swrs with lflf or r lovr. Pur r lovr n pur lflf s wll s th r lovr/grss mixtur gv highst yils. Aftr on growing sson th ropp swrs lft out 15 kg N h -1 on vrg in rop rsius (roots n stul) on th fil. Thr wr no signifint iffrns twn th ropp stns. Th grn mnur swrs lft t lst 21 kg N h -1 in form of mulh, roots n stul on th fil. Du to vry wll vlop, y th first mulhing ut not

4 ngtivly fft nt of stolons, th mulh swrs with whit lovr lft highr nitrogn mounts thn th swrs with lflf or r lovr. Figur 2 shows th highly signifint intrtions of lgum spis, s mixtur n mngmnt on N 2 -fixtion lult with th Totl-N-iffrn mtho s on th N- mounts in hrvstl plnt mtril, mulh n rop rsius unr onsirtion of th CCl 2 -xtrtl soil-n frtions. All ropp swrs fix highr mounts of N thn th mulh ons. With n vrg of 33 kg N h -1 th ropp swrs with lflf or r lovr fix t lst 5 kg N h -1 mor thn th ropp swrs with whit lovr. In th mulh systm th stns with whit lovr rh highr fixtion rts thn th swrs with th othr two lgum spis. Figur 2 lso prsnts th fft of vrious omintions of lgum spis, s mixtur n mngmnt on grin yil n ru protin ontnt of wintr wht following forg lgum stns. Wht following mulh grss/lgum swrs show highr grin yils thn wht ftr ropp swrs. A rson for this my th highr mounts of N in th not hrvst plnt prts of th grn mnur stns. Th grin yil of wintr wht ftr mulh swrs ws not signifintly fft y th hoi of pring lgum spis or s mixtur. With ropp swr s pring ultur th grin yil ws nrly 1 t h -1 highr with whit lovr thn with r lovr or lflf s pring lgum. As ll pring ropp swrs lft th sm mounts of rsiu nitrogn on th fil, rson for grin yil iffrns my iffrnt C/N rtios or N onntrtions in th rop rsius of th iffrnt swrs. Without itionl frtilistion non of th iffrnt omintions of lgum spis, s mixtur n mngmnt rh th ru protin ontnt of king wht. Aftr lultion of th mount of N rmov from th fil with wht grin s on grin yil n ru protin ontnt, 1 kg N h -1 will rmov ftr grn mnur, whil ftr ropp grss/lgum 8 kg N h -1 wr rmov from th fil. A omprison of th rmov N in grin with th N inputs through roots, stul n mulh of th pring lgum swr show highr nitrogn us ffiiny ftr ropp thn ftr mulh swrs. Th high nitrogn input from grn mnur of t lst 21 kg N h -1, n th iffrn twn N-input n N-output ftr ths swrs of t lst 11 kg N h -1 inits n inrs lhing risk ftr grn mnur inorportion s wll s ftr grin hrvst. In xprimnt 2 ll ftors fft th onsir vrils signifintly. Th iffrnt vrils influn y vrious omintions of s mixtur n mngmnt r prsnt in Figur 3 n 4 s n vrg of th two onsir ompnion grss spis prnnil n Itlin rygrss. Figur 3 shows tht th ry mttr proution in 1995 ws minly fft y th mngmnt. Cropp swrs with lovr rh highr ry mttr proution thn th mulh ons. Cropp lys with lovr in proution yr two hiv highr ry mttr n N-yils thn th swrs in th first proution yr. Contrry to th DM-yils of s mixturs with lovr, pur grss show th highst DM-yils in th mulh systm n th lowst DM-yils in yr two of forg proution. Whil in h of th two ropp systms thr ws no fft of th s mixtur on th DM-yils of swrs with r lovr, n inrs of s mixtur lovr ontnt l to n inrs of N-yils. Aoring to th rsiu N oth xprimnts h omprl rsults. On vrg th mulh vrints with lovr in th s mixtur lft pproximtly 2 kg N h -1 s mulh, stul n roots whil omprl mixturs in th ropp systms lft out 11 kg N h -1 in rop rsius on th fil. Whil thr ws no iffrn in rsiu N twn th iffrnt s mixturs with lovr in th ropp systm, n inrs of r lovr ontnt in th s mixtur l to n inrs of th N mount in th not hrvstl plnt prts.

5 Figur 3 lso shows th fft of s mixtur n mngmnt on th N-onntrtion in th not hrvstl plnt prts. In this s th vrition twn.9 % of OM n 2.8 % of OM is minly us y th vrition of r lovr ontnt in th s mixtur. An inrs of s mixtur lovr ontnt l to n inrs in nitrogn ontnt. All ropp swrs with r lovr in xprimnt 2 hiv highr lovr ontnts in DM-yil n N-fixtion thn th mulh ons. With n vrg of mor thn 4 kg N h -1 th ropp swrs in th son growth prio wr mor fftiv thn oth on yr ol swrs. Clovr ontnts in DM-yil of swrs in th son proution yr wr highr thn in oth on yr ol swrs. In ll swr typs lovr rih s mixturs rh highr lovr ontnts n N-fixtion thn s mixturs with lowr lovr ontnt. Figur 4 shows th influn of s mixtur n mngmnt of r lovr/grss on grin yil, ru protin ontnt n on nitrogn uptk t iffrnt stgs of susqunt wht. Clovr ontnt in th s mixtur ount for most of th ourring vrition of th vrils onsir in th susqunt wht. A high s mixtur lovr ontnt l to high grin yils n lso to high N-uptk for wintr s wll s t mturity. An inrs lovr ontnt in th s mixtur inrs lso th mounts of N tht n rmov with th grin. Th mulh pur r lovr swr with its vry high mount of N in rop rsius rh th highst grin yil, N-uptk n grin protin ontnt in th susqunt wintr wht. Only th wht following this swr hiv king qulity without itionl frtilistion, ut it is notworthy tht this onomilly sirl grin yil n qulity only ws hiv through n input of 26 kg N h -1 in form of n inorportion of vry lightly minrlisl plnt mtril with n N-onntrtion of 2.8 % of OM whih my l to lhing losss of nitrogn. A omprison of lovr ontnt in DM-yil n th ourring vrition of th vrils onsir inits orrltion twn lovr ontnt in DMyil n N-yil, N 2 -fixtion, N-onntrtion in not hrvstl plnt prts s wll s grin-yil n N-uptk of th susqunt rop. Th rsults show tht ry mttr proution, N-yil, rsiu nitrogn n N-fixtion of lgum/grss mixturs n influn y vrious omintions of lgum spis, s mixtur, mngmnt n urtion of ly. Th sm ftors lso influn grin yil, N- uptk n protin ontnt of susqunt wintr wht. Th nm ftors hv to onsir whil plnning rop rottions. Rfrns Bowly, S.R., Tylor, N.L. & Doughrty, C.T. (1984). Physiology n Morphology of r Clovr. Avns in Agronomy 37, Hgmir, H.U. (1986). Ür i Stikstoffvrsorgung von Wintr-Wizn un Wintr- Roggn urh Lguminosnvorfrüht, rgstllt nhn von Exprimntn uf inm vihlos wirtshfttn orgnish-iologishn Akrutri uf r Shwäishn Al. Dissrttion, Univrsität Hohnhim, Institut für Pflnznu. Hry, R.W.F. & Holstn, H.D. (1975). Mthos for msurmnt of initrogn fixtion. StIV.: Agronomy n Eology, pp John Wily n Sons, Nw York. Lru, T.A. & Pttrson, T.G., (1981). How muh nitrogn o lgums fix? Avns in Agronomy 34, MBrtny, J. (1981). Proutivity of r lovr grown lon n with ompnion grsss ovr four-yr prio. Grss Forg Si. 36,

6 Tls n figurs Figur 1. Efft of mngmnt on ry mttr proution, hrvst N-yil n N in rop rsius of thr lgum spis in two iffrnt s mixturs (Hohnshuln 1997). t DM/h DM-Proution CR 5% = 1.5 t DM 5 f 2.5 ropp pur lgum ropp lgum/grssmixtur grn mnur pur lgum grn mnur lgum/grssmixtur kg N/h Hrvst N-Yil CR 5% = 42.5 kg N 1 ropp pur lgum ropp lgum/grssmixtur grn mnur pur lgum grn mnur lgum/grssmixtur kg N/h N in Crop Rsius CR 5% = 35.7 kg N ropp pur lgum ropp lgum/grssmixtur grn mnur pur lgum grn mnur lgum/grssmixtur Lgum spis: r lovr lflf whit lovr (Mns with th sm lttr r not signifintly iffrnt)

7 Figur 2. Efft of mngmnt, lgum spis n s mixtur of lgum/grss on N 2 - fixtion (Hohnshuln 1997) n on grin yil n grin ru protin ontnt of susqunt wht (Hohnshuln 1998). kg N/h/yr N-Fixtion CR 5% = 52.1 kg N 1 ropp pur lgum ropp lgum/grssmixtur grn mnur pur lgum grn mnur lgum/grssmixtur t DM/h Grin Yil of Susqunt Wintr Wht CR 5% = 1.4 t DM ropp pur lgum ropp lgum/grssmixtur grn mnur pur lgum grn mnur lgum/grssmixtur % of DM 14 not signifint ropp ropp pur lgum/grsslgum mixtur Lgum spis: Grin Cru Protin Contnt of Susqunt Wintr Wht r lovr grn mnur pur lgum lflf (Mns with th sm lttr r not signifintly iffrnt) grn mnur lgum/grssmixtur whit lovr

8 Figur 3. Efft of mngmnt of iffrnt r lovr/grss s mixturs on ry mttr proution, lovr ontn, hrvst N-yil, N in plnt rsius, N-onntrtion in plnt rsius n N 2 -fixtion (Hohnshuln 1995). t DM/h N-onntrtion in Plnt rsius kg N/h DM-Proution CR 5% = 2.4 t DM 1 yr ol 1 yr ol 2 yr ol swr swr swr grn mnur ropp ropp Hrvst N-Yil f CR 5% = 62.1 kg N 1 yr ol 1 yr ol 2 yr ol swr swr swr grn mnur ropp ropp f CR 5% =,35 % N of OM 1 yr ol 1 yr ol 2 yr ol swr swr swr grn mnur ropp ropp f g Clovr Contnt of Grss/ Clovr-Mixturs % of DM yil 1 CR 5% = 14.2 % kg N/h yr ol 1 yr ol 2 yr ol swr swr swr grn mnur ropp ropp N in Plnt Rsius CR = 4.7 kg N 1 yr ol 1 yr ol 2 yr ol swr swr swr grn mnur ropp ropp N-Fixtion kg N/h/yr CR 5% = 89.9 kg N yr ol 1 yr ol 2 yr ol swr swr swr grn mnur ropp ropp

9 Figur 4. Efft of mngmnt n s mixtur of r lovr grss on grin yil n grin ru protin ontnt, grin N-mount n N-uptk t iffrnt stgs of susqunt wht (Hohnshuln 1996). Wht N-Uptk in Autumn kg N/h CR 5% =.6 kg N yr ol 1 yr ol 2 yr ol swr swr swr grn mnur ropp ropp Wht N-Uptk t Mturity kg N/h CR 5% = 15.9 kg N f fg 5 g fg 25 kg N/h yr ol 1 yr ol 2 yr ol swr swr swr grn mnur ropp ropp N in Wht Grin CR 5% = 13.7 kg N g f fg 1 yr ol 1 yr ol 2 yr ol swr swr swr grn mnur ropp ropp fg t DM/h Grin Cru Protin Contnt of Wht % of DM yr ol 1 yr ol 2 yr ol swr swr swr grn mnur ropp ropp Wht Grin Yil CR =.5 t DM 1 % r lovr 1 yr ol 1 yr ol 2 yr ol swr swr swr grn mnur ropp ropp 67 % r lovr + 33 % grss 33 % r lovr + 67 % grss 1 % grss (Mns with th sm lttr r not signifintly iffrnt) S mixtur of pring rop:

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