V. Discusión, Conclusiones, Recomendaciones, Limitaciones
5.1. Discusión
20 . I n li ne wi th the New Zealand Government Pri nt i ng offi ce
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the followi ng symbols are u sed i n all tables figure not ava ilableamou nt too small to be expres sed nil
CHAPTER 1
SOI LS , AG R I CULTURE , AND SOI L-AMENDI NG TECHNOLOGY I N N EW ZEALAND : A PREL I M I NARY FRAMEWORK
Soi l amend i n g 1 i s the key to the pre-emi nent
producti v i ty2 of New Zeal and • s agri cu l ture 3 (Moran , 1 974 , 1 24 ) . The country • s s o i l s , havi ng evol ved i n cond i ti on s of geol og i ca l i ns tabi l i ty , are you thfu l and vari ed i n nature ( Da l y , 1 973 , 1 1 ) . Moreove r , they often l ac k natural fert i l i ty and a re commonly defi c i ent i n mi nera l s
(Moran , 1 974 , 1 2 5 ) . Recogn i z i ng the part pl ayed by these edaph i c l im i tati o n s to agri c u l tural producti v i ty has been a fundamental s te p i n the crea ti on , i n tens i f i ca t i on , a n d refi n ement o f t h e nation • s grassl and ecosystems 4 for over a century .
To a l arge ex ten t i n i ti a l dec i s i ons made i n the fo rma ti ve yea rs of col on i za t i on s trongly i nfl u enced the s trateg i es pursued to e s tabl i s h gras s l and ecosys tems . Wi th col on i zati on and frontier expan s i on came the d i ffu s i on of the European concept of farmi ng before the pecu l i a r i ti es of t he New Zea l and env i ronment were a pprec i ated . Austra l i an experi ence i n exten s i ve gra z i n g en terpri ses 5 based on Eu ropea n g ra s ses and s tock provi ded a u sefu l pattern to fol l ow . Accord i n gl y , s owi ng l and to pa s tu re became the practi ce . However , the deter i ora ti on of the gra s s l ands soon posed s i gn i fi cant probl ems for the early farme rs . As l ong a s the area of occupi ed l and cou l d be extended , producti on cou l d be ma i nta i ned by expan s i on a l one . In the l ate n i ne teenth cen tu ry , a s the l i mi ts of the frontier were be i ng reached and enter pri se c hanges became poss i b l e , more atten t i o n began to be pa i d to i ncreas i n g the producti v i ty of the l and .
Match i ng pl a n t requi rements and soi l ferti l i ty wa s seen a s the key to the product i on process ( Smal l fi el d , 1 947a , 1 69 ) . I t was f i r s t hel d that the pl ants empl oyed s hou l d b e a l tered to s u i t exi s ti ng s o i l ferti l i ty l evel s . On ly l a ter was i t sugges ted from the work a t the Rothams ted and Coc kl e Park expe r i menta l f9rms in Bri ta i n that i nc re a s i ng these l evel s cou l d s u s ta i n the ecosys tems seen as mos t p rodu c t i v e from European experi enc e . Thi s technol ogy6 , accord i ngl y , was a pp l i ed to improve s o i l -nutr i ent l evel s . E ffort came to be devoted to u nrave l l i ng the essen t i a l fea tures of the b i ol ogi ca l sys tem i nvol ved to i ncrea s e
the effec ti veness o f soi l - amend i ng techn i ques . The opti on of seek i ng pl ants demand i n g l ower soi l - ferti l i ty l evel s wa s not pursued a s
v i gorous l y and s o contri buted l es s to ex i s ti ng producti on tec h n i ques ( Fi l mer , 1 9 55 , 1 2 ; Corki l l , 1 97 1 , 1 2 , 1 4 ) . Only with the a ppearance of l i mi ta ti ons i n the preva i l i ng ecosys tems by the 1 960s was i ntere st i n t he above opti on renewed ( Daly , 1 973 , 2 5 ) .
The pr i nc i pal gra s s l and ecosys tem whi ch emerged wa s ba s ed on perenn i al ryegrass and wh i te cl over, wh i ch 1 from North Cape to Stewa rt I s l and g i ve a u n i form appearance to nearly 9 mi l l i on hec ta re s of sown pastures1 ( Da l y , 1 973 , 2 1 ) . I ts c ha racteri s ti c fl ouri sh i ng grass g rowth s tems from the l e gumes pres en t , pri nci pa l ly cl overs , wh i c h s u p ply the n i trates needed through the i r symb i o t i c rel a t i ons h i p wi th n i trogen-fi x i ng so i l bac ter i a . Thus , i f the nutri tional req u i rements of the c l overs are met , man can expl o i t thi s sys tem and obvi a te the I need for n i trogenou s ferti l i zers . As c l overs prefer neutral soi l s , l i m i ng soi l s w i th too h i g h an aci d i ty l evel i s a fi rst ste p i n successfu l ly e s tabl i s h i ng th i s ecosys tem . Furthermore , the ca l ci um i n l i me favourably affec ts the forma t i on of the root nodu l es where the n i trogen-fi x i n g bacteri a res i de , so contri buti ng to a grea ter supply of ni tra tes ( Brady , 1 97 4 , 435 ) . Whi l e requ i ri ng the s ame nu tr i ents as other pa s ture pl ants , l e gumes have a parti cu l ar need for phosphate
( Brady , 1 974 , 456 ) . The genera l defi c i ency of th i s mi neral i n New Zea l and soi l s was the pri nci pal l i mi ta t i on to be overcome by soi l
amend i ng . The recogni t i on of the rel a t i on of l i me to pho s p ha te u p ta ke , the rol e of trace e l ements i n pl a n t nu tri ti on a nd the i mportance of the l egumi nous component to the pa stu re sward were to fol l ow .
The u ti l i zati on o f l and for pa s ture had become a fea ture of New Zea l and agri c u l ture by ·1 86 1 when 70 percent of the area of i mproved farml and was s o empl oyed ( Statistics
of
New Zealand, 1 861 , Tabl e No . 51 ) . By the early years of the twenti eth century thi s fi g u re had r i sen even h i gher , and to 1 97 0 , rema i ned i n the 88 to 90 p ercent range 7 • The types of pas ture l and have vari ed i n thei r c h a racter , d i str i buti on and produc t i vi ty . T he c l ima te , soi l , and rel i ef cou l d not a l l be managed to ac h i eve the u n i formi ty of pas tu re typ e desi red . For exampl e , of the 8 . 5 mi l l i on hectares of sown pas ture , s ome 4 . 5 mi l l i on a re fou nd on u np l oug habl e s l o pes ( Wh i te , 1 97 3 , 261 ) . The attrac ti venes s of the s teep s l opes i s an ou tcome of the l i m i teds u ppl i es of fl at and u nd u l a t i ng l and of the a n t i c i pated profi tabi l i ty of graz i ng ; Forest , fern , and scrub were cl eared from h i l l country
to soi l amend i ng , howeve r . S i gns of dec l i n i ng l and producti v i ty a ppea red { Gou l d , 1 976 , 1 9 ; G i b bs , 1 974 , 1 74-1 7 5 ) ; yet a soru ti on to the general probl em of ens u ri ng adequate soi l ferti l i ty wa s not
fou nd q u i c kl y . Many decades of conti n u i ng experimentati on were needed. before s i gn i fi cant succes s was achi eved but thi s success wa s s pectacu l a r . The d i sti ngu i s hed sci enti s t , S i r E . B . L evy ( 1 955 , 9 ) , has c l a i med that the ' i n i mi tab l e g ras sl and c l i mate ' wa s ' l i nked wi th s o i l ferti l i ty a nd w i th pl ants and a n i ma l s that can expl oi t to the fu l l the potenti a l i ti es of our [New Zea l and ' s ] c l i ma te . '
A fi rst s te p i n thi s l i nkage of c l i mate , soi l ferti l i ty , pl ants , and a n i ma l s wa s the repl a c ement of i nd i genous grasses wi th more
prod ucti ve exot i c s . The use of these more demand i ng gra sses depl eted ferti l i ty a nd prompted a s earch for ways to ma i n ta i n ferti l i ty to s u s ta i n them ( Levy , 1 970 , 48 ) . The techn i que of amendi ng the so i l throu gh the add i t i on of n u t r i ents and the con tro l of aci d i ty wa s a cri ti cal l y i mportant devel opment .
The effec ts of thi s technol ogy a re compl ex , i nvol v i ng the bi ol ogical and bi ochem i c a l processes through whi ch s o i l and p l a nts i nteract to c reate feed for a n i mal s . These i n teracti ons can be reg u l ated by t he d i stri buti on of appropri ate chemical and bi o l ogi c a l ma teri al s i t was bei ng d i scovered i n Europe a t the time o f New
Zea l and ' s col o n i zati on by Bri ta i n . The techni ques devel oped were i ncorporated i nto the technol ogy whi ch came to be u sed to overc ome the newly encoun tered production d i ffi cu l t i e s . The transmi s s i on of thi s i nformati on to farmers , and the organi zati on of i nsti tut i ons to res earch i t and further devel op i t for use i n the New Zea l and env i ron ment were i mportant i n the crea t i on of a ppropri ate farmi ng practi ces . T he concern wi th the tec hn i ca l a s pects of so i l amendi ng enta i l ed t he devel opment of s u i tabl e mec ha n i cal s p readi ng dev i ce s and of ma nagement tec hni ques . The use of both pl ayed a key part in the emerg i ng
farm i ng systems . The a p pl i cati on of these techniques refl ec ted a reappra i sal of the prod u c ti on poten ti a l o
f
the l and i tsel f .Soi l amend i ng wa s more than j u s t a mea n s of l i n k i ng l i v estock product i on w i th cl i mate potenti a l i ti es . I n s u s ta i n i ng the g ra s s l a nd economy , s o i l -amend i ng tech nol ogy may have al tered the course of New Zeal and ' s economi c devel opment . Many factors s erved to perpe tuate
the gra s s l and u nderpi n n i ng of the economy , to the d i sadvantage of the non-agr i c u l tural s ectors . The hi g h ferti l i ty dema nds of the ryegra s s -
whi te-cl over pasture , the mos t produc ti ve type ( Levy , 1 97 0 , 70 ) , were met by an u n swervi ng commi tment to i mprovi ng so i l ferti l i ty , ra ther than by expl ori ng the al terna ti ve strategy of crea t i ng grasses wi th l ower fert i l i ty demand s . The fa i th in so i l -amend i ng technol ogy had i mporta nt rami fic ati ons . I t became a focal poi nt for i nventi ve acti vi ty , encouraged a l ong -term s tabi l i ty i n agr i c u l tura l pat te rns , a nd fac i l i tated the conti nued domi nance of the agri c u l tural s ec tor . The success of these su pport i ve trend s further confi rmed the fa i th
i n s o i l -amend i ng technol ogy a nd , when abetted by a combi nation of external and i nterna l fa ctors , cons ti tu ted a cond i ti on i n g i nf l u ence on the searc h for a nd recepti v i ty towards i mprovements i n soi l - amendi ng capabi l i ty .
TH E FRAMEWORK
Thi s d i s s ertat i on cons i ders the i ntroducti on , adopti on ,
ada ptati on, and g eneration of soi l -amend i ng technol ogy i n New Zeal and . The conceptua l i za t i on of s o i l -amend i ng tec hni ques a s i nnovati o n s ,
embodyi ng the a ppl ication of knowl edge to production , and of the round s of adj u s tment fol l owing the i r adopt i o n a s technol ogi cal c hanges ,
provi des a ba s i s for trac i ng the i ncorporati on of soi l -ame nd i ng tech nol ogy i nto New Zeal and agri c u l ture . Empl oyi ng a framework embrac i ng the rel ated noti ons of economic growth a nd economi c devel opment 8 al l ows the expl ora t i o n of the ways i n wh i c h cha ng i ng tec hnol ogy e nab l es and i nduces produ cti v i ty i mprovements and i ntroduces enti rel y new a pproaches to product i ve acti v i ty . T h e former bri ng about growth i n the form of sca l ar chang e s , whi l e the l atter s t i mu l ate devel opment through the process of restructuri ng economi c rel ati onshi p s . The causa l i ty of the re l a t i on s h i p between techno l og i cal c hange , growth , a nd devel opmen t i s thus a centra l concern of t h i s d i s se rtati on .
The i nterconnecti on between tec hnol ogical c ha nge i n agri c u l ture a nd economi c devel opment can be u s efu l l y d i scussed by reference to economi c p rod ucti on theory . Convent i onal