search
for
 About Bioline  All Journals  Testimonials  Membership  News  Donations


African Crop Science Journal
African Crop Science Society
ISSN: 1021-9730
EISSN: 2072-6589
Vol. 4, No. 3, 1996, pp. 305-313
Bioline Code: cs96070
Full paper language: English
Document type: Research Article
Document available free of charge

African Crop Science Journal, Vol. 4, No. 3, 1996, pp. 305-313

 fr
Davis, C.K. & Vanderlip, R.L.

Résumé

Les conditions climatiques etant extrement variables
permettent aux agriculteurs du Botswana de planter apres
chaque pluie abondante.  Les techniques des gestions variees,
par exemple, le systeme de labourer deux fois a ete propose
pour reduire la carence et l'augmentation en production de
sorgho.  Le modele de l'augmentation du sorgho qui est connu
sous le nom de SORKAM, etait utilise pour estimer les effets
du potentiel de la reduction de l'effet de la carence du
systeme de labourer deux fois sur la stabilite de production
du sorgho pour quatre locations (six sols) et les donnees des
climats pour une duree de 40 ans.  La reduction de carence
simultanee a augmentee la production du sorgho a 32% et sur le
sol a peu pres de 50% d'argile.  La plus petite augmentation
de production sur les sols ont de grandes capacites de
conserver de l'eau, qui occasionne le stockage d'une grande
quantite d'eau.  En general, malgre le double systeme de
labourer ce qui retarde le premiere saison de planter tot a
une moyenne des productions par rapport au planter tot, aucune
date de planter n'etait optimum et les variations en
production etaient superieures par rapport a toutes les dates. 
les distributions des frequences cumulatives ont montrees que
l'avantage de carence reduite n'etait par seulement dependante
en location (capacite de conserver de l'eau),  Mais aussi au
niveau de production.  Dans toutes les locations aux bas
niveau de production, a reduit la carence soit diminuer,
l'incidence totale de l'echec de la plante.

Mots Clés
Deux cultures, sorgho bicolor, capacite de conserver de l'eau

 
 en Simulating the potential effects of reducing runoff and planting date on sorghum yields in Botswana
Davis, C.K. & Vanderlip, R.L.

Abstract

Extremely variable climatic conditions cause Botswana farmers
to plant after each significant rain.  Various management
techniques, such as double ploughing, have been proposed to
reduce runoff and increase sorghum yields.  SORKAM, a computer
growth model for sorghum, was used to estimate the potential
effects of the reduced runoff effect of double ploughing on
sorghum yields and yield stability for four locations (six
soils) and climatic data for 40 years.  Simulated reduced
runoff increased sorghum yields up to 32% on a soil with about
50% clay.  The smallest yield increase, 1%, was on a soil with
90% sand.  Reduced runoff increased yields most on soils that
have higher water holding capacities, allowing greater water
storage.  Although double ploughing, in general, would delay
the first planting and early planting had higher average
yields than late planting, no date of planting was optimum and
ranges in yield were great for all dates.  Cumulative
frequency distributions showed that the advantage of reduced
runoff not only was dependent on location (water holding
capacity) but also on yield level.  At all locations at low
yield levels, reduced runoff either decreased yield or
inceased the incidence of total crop failure.

Keywords
Double ploughing, Sorghum bicolor, water holding capacity

 
© Copyright 1996 - African Crop Science Society

Home Faq Resources Email Bioline
© Bioline International, 1989 - 2022, Site last up-dated on 19-Jan-2022.
Site created and maintained by the Reference Center on Environmental Information, CRIA, Brazil
System hosted by the Internet Data Center of Rede Nacional de Ensino e Pesquisa, RNP, Brazil