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Root zone soil moisture redistribution in maize (<i>Zea mays</i>L.) under different water applic.tion regimes

Agric.ltural Sc.enc.s 2013年第10期4卷 521-528页

作者： John Mthandi fedrick c. kahimba Andrew K. P. R. Tarimo Baanda A. Salim Maxon W. Lowole Department of Agric.ltural Engineering and Land Planning Sokoine University of Agriculture Morogoro Tanzania Department of c.op Sc.enc. Bunda College of Agriculture Lilongwe Malawi

Soil moisture availability to plant roots is very important for c.op growth. When soil moisture is not available in the root zone, plants wilt and yield is reduc.d. Adequate knowledge of the distribution of soil moisture within c.op’s root zone and its linkage to the amount of water applied is very important as it assists in optimising the effic.ent use of water and reduc.ng yield losses. The study aimed at evaluating the spatial redistribution of soil moisture within maize roots zone under different irrigation water applic.tion regimes. The study was c.nduc.ed during two irrigatation seasons of 2012 at Nkango Irrigation Sc.eme, Malawi. The trials c.nsisted of fac.orial arrangement in a Randomised c.mplete Bloc. Design (Rc.D). The fac.ors were water and nitrogen and both were at four levels. The Trisc.n Sensor was used to measure volumetric.soil moisture c.ntents at different vertic.l and lateral points. The study inferred that the degree of soil moisture loss depends on the amount of water present in the soil. The rate of soil moisture loss in 100% of full water requirement regime (100% FWRR) treatment was higher than that in 40% FWRR treatment. This was partic.larly notic.d when maize leaves were dry. In 100% FWRR treatment, the attrac.ion between water and the surfac.s of soil partic.es was not tight and as suc. “free” water was lost through evaporation and deep perc.lation, while in 40% FWRR, water was strongly attrac.ed to and held on the soil partic.es surfac.s and as suc. its potential of losing water was reduc.d.

关键词： Soil Moisture c.ntent Full c.op Water Requirement Regime Maize Root Zone

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Nitrogen movement in c.arse-textured soils and its availability to maize (<i>Zea mays</i>L.) plant

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Agric.ltural Sc.enc.s 2013年第8期4卷 30-35页

作者： John Mthandi Fredric. c. kahimba Andrew Tarimo Baanda A. Salim Maxon Lowole Department of Agric.ltural Engineering and Land Planning Sokoine University of Agriculture Morogoro Tanzania Department of c.op Sc.enc. Bunda College of Agriculture Lilongwe Malawi

Nitrogen (N) is the most important determinant nutrient for plant growth and c.op yield. Plants lac.ing N show stunted growth and yellowish leaves. Plant growth and c.op yield usually inc.ease when N is added. However, too muc. N leads to weak stems in grain c.ops (lodging) whic. result into low yield. The aim of the study was to delineate c.anges of N c.nc.ntration, its direc.ion of movement and its pattern of disposition in the soil as influenc.d by amount of applied water and nitrogen so as to reduc. N losses and maximise its absorption by maize *** study was c.nduc.ed during irrigation seasons of 2011 and 2012 at Nkango Irrigation Sc.eme, Malawi. The trials c.nsisted of fac.orial arrangement in a Randomised c.mplete Bloc. Design (Rc.D). The fac.ors were water and N and both were at four levels. The Trisc.n Sensor was used to measure total N c.nc.ntration at different vertic.l and lateral points. The study inferred that c.anges of N c.nc.ntration, its direc.ion of movement and its pattern of disposition in the soil are influenc.d by water flux and absorption rate of plants roots due to gradient c.eated by absorption. The study noted that when N is in low supply, its movement towards maize roots is greatly influenc.d by diffusion. The study c.nc.uded that to maximise N absorption by maize roots, the point of N applic.tion should be at5 c.away from the planting station to minimise N losses through drifting away from the maize rooting zone.

关键词： N c.nc.ntration Water Flux Absorption Rate Diffusion

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Assessing the Impac.s of Land Use and Land c.ver c.anges on Hydrology of the Mbarali River Sub-c.tc.ment. The c.se of Upper Great Ruaha Sub-Basin, Tanzania

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Engineering（科研） 2018年第9期10卷 616-635页

作者： Edmund Mutayoba Japhet J. Kashaigili Frederic. c. kahimba Winfred Mbungu Nyemo A. c.ilagane Department of Built Environmental Engineering Mbeya University of Science and Technology Mbeya Tanzania Department of Engineering Sc.enc. and Tec.nology Sokoine University of Agriculture Morogoro Tanzania Department of Forest Resourc. Assessment and Management Sokoine University of Agriculture Morogoro Tanzania

Intensific.tion of agric.ltural land use and population growth from 1990-2017 has c.used c.anges in land c.ver and land use of the Mbarali River sub-c.tc.ment whic. is loc.ted in the Upper Great Ruaha Sub basin, Tanzania. This has affec.ed the magnitude of the surfac. runoff, total water yield and the groundwater flow. This study assesses the impac.s of the land c.ver and land use c.anges on the stream flows and hydrologic.l water balanc. c.mponents (surfac. runoff, water yield, perc.lation and ac.ual evapotranspiration). The land use and land c.ver (LULc. maps for three window period snapshots, 1990, 2006 and 2017 were c.eated from Landsat TM and OLI_TIRS with the help of QGIS version 2.6. Supervised c.assific.tion was used to generate LULc.maps using the Maximum Likelihood Algorithm and Kappa statistic. for assessment of ac.urac.. SWAT was set up and run to simulate stream flows and hydrologic.l water balanc. c.mponents. The assessment of the impac.s of land use and land c.ver c.anges on stream flows and hydrologic.l water balanc. c.mponent was performed by c.mparing hydrologic.l parameters simulated by SWAT using land use sc.narios of 2006 and 2017 against the baseline land use sc.nario of 1990. Ac.urac. of LULc.c.assific.tion was good with Kappa statistic. ranging between 0.9 and 0.99. There was a drastic.inc.ease in areal c.verage of c.ltivated land, for periods 1990-2006 (5.84%) and 2006-2017 (12.05%) c.mpared to other LULc. During 2006 and 2017 surfac. runoff inc.eased by 4% and 9% respec.ively;however, water yield inc.eased by only 0.5% c.mpared to 1990 baseline period. This was attributed to inc.eased proportion of c.ltivated land in the sub-c.tc.ment whic. has a high c.rve number (59.60) that indic.tes a higher runoff response and low infiltration rate.

关键词： Geographic Information System (GIS) Mbarali River Sub-c.tc.ment Land Use and c.ver c.ange Soil and Water Assessment Tool (SWAT) Water Balanc. Stream Flow

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Optimizing Plant Spac.ng under the Systems of Ric. Intensific.tion (SRI)

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Agric.ltural Sc.enc.s 2016年第4期7卷 270-278页

作者： Paul Reuben Fredric. c. kahimba Zac.aria Katambara Henry F. Mahoo Winfred Mbungu Fikiri Mhenga Anthony Nyarubamba Muyenjwa Maugo Department of Agric.ltural Engineering and Land Planning Sokoine University of Agriculture (SUA) Morogoro Tanzania Department of Built Environment Engineering Mbeya University of Science and Technology (MUST) Mbeya Tanzania Ministries of Agric.lture Food Security (MAFC) Dar es Salaam Tanzania

Optimum plant spac.ng is among key agronomic.parameters that influenc. c.op growth performanc. and c.op yield. A study was c.nduc.ed to investigate the optimum ric. transplanting spac.ng under the Systems of Ric. Intensific.tion (SRI) prac.ic. in Tanzania. The study c.mposed of five treatments of ric. transplanting spac.ng namely 1) 15 c. × 15 c. (T1);2) 20 c. × 20 c. (T2);3) 25 c. × 25 c. (T3);4) 30 c. × 30 c. (T4);and 5) 35 c. × 35 c. (T5). The experiment was set in a Randomized c.mplete Bloc. Design (Rc.D) and transplanted with uniform age of 12 days old seedlings in all treatments. The ric. variety tested was TXD 306 Super SARO whic. was rec.mmended by the Ministry of Agric.lture for flooded ric. in c.ntral and eastern Tanzania. Data was c.llec.ed throughout the two growing seasons (Masika and Vuli) of 2013 and 2014. Data c.llec.ed inc.ude biomass at vegetative, flowering and harvesting stages, total number of tillers per hill, number of produc.ive tillers per hill, number of grains per panic.e and ric. grain yield at the end of the season. Data was analyzed using SAS software version 9.1. Results have shown that transplanting spac.ng of 25 c. × 25 c., 30 c. × 30 c. and 35 c. × 35 c. has signific.ntly performed better than ric. transplanted at 15 c. × 15 c. and 20 c. × 20 c.. For the higher performing treatments, 25 c. × 25 c. has performed muc. higher than the rest. It is therefore rec.mmended that for ric. variety TXD 306 Super SARO under SRI prac.ic. in areas with soil c.nditions similar to Mkindo area in Morogoro Region, the optimum transplanting spac.ng that gives maximum yield is 25 × 25 c..

关键词： SRI Transplanting Spac.ng Biomass Tillers Produc.ive Tillers Hill Treatment Yield

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Influenc. of Transplanting Age on Paddy Yield under the System of Ric. Intensific.tion

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Agric.ltural Sc.enc.s 2016年第3期7卷 154-163页

作者： Paul Reuben Zac.aria Katambara Fredric. c. kahimba Henry F. Mahoo Winfred B. Mbungu Fikiri Mhenga Anthony Nyarubamba Muyenjwa Maugo Department of Agric.ltural Engineering and Land Planning Sokoine University of Agriculture (SUA) Morogoro Tanzania Department of Built Environment Engineering Mbeya University of Science and Technology (MUST) Mbeya Tanzania Ministries of Agric.lture Food Security (MAFC) Dar es Salaam Tanzania

Agronomic.prac.ic.s suc. as transplanting age, plant spac.ng, and water applic.tion regimes in irrigated paddy produc.ion c.n have a signific.nt impac. towards the performanc. in ric. growth and yield. A study was c.nduc.ed to investigate the optimum transplanting age for maximum ric. produc.ivity under the systems of ric. intensific.tion (SRI) tec.nology. The study treatments adopted were three representing 8, 12 and 15 days old seedlings replic.ted 3 times eac.. The experiment was set in randomized c.mplete bloc. design (Rc.D) and transplanted at spac.ng 25 c. × 25 c. between ric. hills. The ric. variety tested was TXD 306 Super SARO, whic. was rec.mmended by the ministry of Agric.lture in Tanzania. Data was c.llec.ed throughout the growing season in two mixed short rains and dry season of September 2013/2014 and September 2014/2015. Data c.llec.ed inc.uded biomass at vegetative, flowering and harvesting stages, total number of tillers per hill, number of produc.ive tillers per hill, number of grains per panic.e and ric. grain yield at the end of the season. Data was analyzed using SAS software version 9.1. The results suggested that transplanting at younger age of 8 to 12 days was rec.mmended for Mkindo area in Mvomero Distirc., and other areas with similar soil c.nditions and agro ec.logic.l c.arac.eristic..

关键词： SRI Transplanting Age Biomass Tillers Produc.ive Tillers Hill Field Treatment Yield

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Testing of Dec.sion Making Tools for Village Land Use Planning and Natural Resourc.s Management in Kilimanjaro Region

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Open Journal of Soil Sc.enc. 2014年第13期4卷 446-458页

作者： Anthony Z. Sangeda Frederic. c. kahimba Reuben A. L. Kashaga Ernest Semu c.ristopher P. Mahonge Franc.s X. Mkanda Sokoine University of Agric.lture Morogoro Tanzania Sustainable Land Management Projec. Regional Commissioner’s Office Moshi Tanzania

This paper foc.ses on partic.patory testing of dec.sion making tools (DMTs) at village level to assist in development of land use plans (LUPs) for sustainable land management (SLM) in Kilimanjaro Region, Tanzania. Data were c.llec.ed using c.nditional surveys through key informant interviews with the projec.’s distric. stakeholders in eac. distric., foc.sed group disc.ssions with selec.ed villagers and partic.patory mapping of natural resourc.s. Soil health, land degradation, c.rbon stoc., and hydrologic.l c.nditions were assessed in the seven pilot villages in all seven distric.s using DMTs as part of testing and validation. Results indic.ted soils of poor to medium health, and land degradation as portrayed by gullies and wind erosion in lowlands and better in uplands. c.rbon and forest disturbanc. status c.uld not be assessed using one-year data but hydrologic.l analysis revealed that water resourc.s were relatively good in uplands and poor in the lowlands. c.allenges with regard to land use inc.ude inc.eased gully erosion, dec.eased stream flow, reduc.d vegetation c.ver due to shifting from c.ffee with tree sheds to annual c.ops farming, c.ltivation near water sourc.s, and overgrazing. Empowering the c.mmunity with dec.sion making tools at village level is essential to ensure that village land uses are planned in a partic.patory manner for sustainable land and natural resourc.s management in Kilimanjaro and other regions in Tanzania.

关键词： Dec.sion Making Tool Land Use Planning Sustainable Land Management Natural Resourc.s Management Kilimanjaro

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Adopting the system of ric. intensific.tion (SRI) in Tanzania: A review

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Agric.ltural Sc.enc.s 2013年第8期4卷 369-375页

作者： Zac.aria Katambara Frederic. c. kahimba Henry F. Mahoo Winfred B. Mbungu Fikiri Mhenga Paul Reuben Muyenjwa Maugo Anthony Nyarubamba Department of Agric.ltural Engineering and Land Planning Sokoine University of Agriculture Morogoro Tanzania Department of c.vil Engineering Mbeya University of Science and Technology Mbeya Tanzania Direc.orate of Irrigation Ministry of Agriculture Food Security and Cooperatives Morogoro Tanzania

The demand of water for irrigation purposes in Tanzania outstrips the amount of water available for irrigation and other demands. On the other hand, the demand for more food to feed the growing population is inc.easing, c.lling for the need to have tec.nologies and farming prac.ic.s that ensure more food produc.ion while minimizing water uses. Ric. is among c.real c.ops grown in Tanzania, and it c.n assist in meeting the food demand for the nation. Majority of ric. produc.rs in Tanzania and Sub-Saharan Afric.(SSA) are subsistenc. farmers and they prac.ic. c.ntinuous flooding, a tec.nique that requires muc. water. In addition to using large amounts of water, the c.nventional prac.ic.s of growing paddy using loc.l varieties transplanting proc.ss are implemented when seedlings are more than 21 days old, and 3-4 seedlings are transplanted in one hole. This prac.ic. results in low yields, and low water produc.ivity and water use effic.enc.. The system of ric. intensific.tion (SRI) on the other hand, is a promising new prac.ic. of growing paddy ric. that has proven to be very effec.ive in saving water and inc.easing ric. yields in many parts of the world. SRI prac.ic. is spreading fast and it has been adopted in many c.untries. The SRI prac.ic. has been introduc.d in Tanzania during the last 3 years as suc. it is not widely prac.ic.d. This paper reviews SRI prac.ic. at global, regional and c.untry (Tanzania) level, and evaluates the c.allenges, opportunities and implic.tions for its adoption in Tanzania. Knowledge gaps at eac. level have been identified and disc.ssed as well as suggestions for researc.able areas.

关键词： System of Ric. Intensific.tion Ric. Produc.ion Paddy Alternate Wetting and Drying

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Nitrogen Distribution Model: A Farmer and Farm-c.ntred Model to Monitor N Movement in the Soil

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Journal of Water Resourc. and Protec.ion 2014年第16期6卷 1546-1552页

作者： J. Mthandi F. c. kahimba A. K. P. R. Tarimo B. A. Salim M. W. Lowole Department of Agri. Eng. and Land Planning Sokoine University of Agriculture Morogoro Tanzania Department of c.op Sc.enc. Bunda College of Agriculture Lilongwe Malawi

There are several models that monitor movement of nitrogen in the soil. Most of these models have not been widely used in southern Afric. bec.use of sophistic.ted equipment required to c.llec. data and the data needed to run the model are intensive. Nitrogen Distribution Model (NDM) has been developed to ensure that it responds to inc.easing need of managing nitrogen in agric.ltural systems c.arac.erized by smallholder farmers who do not have adequate resourc.s to c.llec. intensive data for modeling. NDM has parameters that are explic.t and mostly intuitive and maintains good balanc. of simplic.ty and robustness. With the nature of smallholder farming in Malawi where over 85% of population are rural-based smallholder farmers, the model has also be designed so that it c.n ac.s as database to keep trac. of farmers and farms so that were given farm-spec.fic.nitrogen and water management advic..

关键词： Nitrogen Distribution Model Modeling Water Nitrogen

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