Cover crops as a compliment to crop residues in Natural Resource Management: Dolichos lablab intercrop with maize (Vumilia K-1) residues with DAP and urea top dressing | Crop Management (Crop Varieties)

Two (2) farmer participatory studies on maize legume croppingsystem were conducted in Northern Tanzania in the districts of Babati, Karatu,Arumeru/Monduli and Hai. The first study was conducted for two seasons in 2009and 2010 in eight (8) locations using Dolichoslablab as the base legume. The second study was conducted in 2010 in n Read more..

Description of the technology or innovation

Two (2) farmer participatory studies on maize legume croppingsystem were conducted in Northern Tanzania in the districts of Babati, Karatu,Arumeru/Monduli and Hai. The first study was conducted for two seasons in 2009and 2010 in eight (8) locations using Dolichoslablab as the base legume. The second study was conducted in 2010 in nine(9) sites and used Dolichos lablaband pigeon peas as the base legumes in maize legume intercrops. Both studiesaimed at identifying and scaling out/promoting best bet options using themother baby approach.

 

About 120 farmers participated in the first study and 270 in thesecond study. Yields, soil data, farmer assessments and economic analyses weredone. Results in the first study indicate that, grain yields ranged from 1.8t/ha to 4.6 t/ha in the second year. The highest mean grain yields were seen inVumilia K-1 (maize variety) intercropped with Dolichos lablab, planted with Di-ammonium phosphate (DAP) at a rateof 22.5 kg/ha N and top dressed with 57.5 kg/ha of urea. This treatment rankednumber one with a relative yield of 160%. This was followed by Vumilia K-1 (maizevariety) at 3.6 tons/ha intercropped with Dolichoslablab with 22.5 kg/ha N from DAP without top dressing, with a relativeyield of 126%. Higher grain yield for Vumilia K-1 was also noted from the babytrials when compared to Situka-1. No significant yield differences (P=0.05)were noted for biomass yields. These technologies were highly ranked by farmersusing absolute, matrix and pair wise rankings. A change in soil chemicalproperties was noted at the surface (0-15 cm depth) with pH rising from anaverage of 6.0 to 7.0; while an increase in organic matter (%OM) was alsoobserved in one of the sites. There was a major increase in total nitrogen from0.14% to 0.5% in nearly all (6 out of 7) sites sampled. Olsen P rose from 0 toas high as 140 mg/kg in five (5) sites, while Calcium (Ca) and Magnesium (Mg)increased from 1.5 and 1.9 cmol/kg to as high as 10.2 and 4.8 cmol/kgrespectively. There was a decrease in Potassium (K) from the soil profile whileSodium (Na) remained relatively constant. These findings clearly suggest thatthe treatments had a positive impact on the physical as well as chemicalproperties of the soil during the first study.

 

On the other hand, results for the second study indicated that;grain yields of the different maize varieties were not statistically (P=0.05)different in all the eight (8) mother demonstration plots harvested. Both covercrops were a good complement to the maize crop residues.


Assessment/reflection on utilization, dissemination & scaling out or up approaches used

The target farmers were mainly maize-legume crop farmers andzero-grazing livestock keepers. On-farm trials were set up in Babati, Karatu,Arumeru/Monduli and Hai districts and were used for scaling up of thetechnologies.


Current situation and future scaling up

The practice is designed to reduce the financial burden for allgender.  The practice also advancesbetter land management where the cover crops conserve soil moisture, reducesoil erosion and add fertility to soil. In this context, improved landmanagement should translate into increased food security and improvednutrition. The practice is important for soil fertility management andrecommended for countries where the rate of inorganic fertilizer application isstill very low.

Economic Considerations

Farmers’ assessment and economic analysis of the results showedthat maize intercropped with pigeon pea was the best option, followed by maize-Dolichos lablab intercrop. The maizemonocrop technology was the least preferred one. However, there was high seeddemand for pigeon pea and Dolichos lablabseed by farmers in the target areas, especially before the start of the secondyear season; indicating a high adoption of the technologies. This practice haselements of using locally available resources (crop residues) for soil fertilityenhancement, which is affordable (some inputs are considered as farm waste)compared to using inorganic fertilizer alone. It also important to note thatusing cover crops and crop residues, reduces costs of weeding and inorganicfertilizer respectively. The practice thus makes optimal use of farm resourcesby converting and conserving otherwise wasted materials.

Gender considerations

The innovation considers all gendercategories and was designed to reduce costs associated with application ofinorganic fertilizer thereby reducing the financial burden for all gendercategories.

Contact details

Peter R. Matowo;

Breeder, Selian Agricultural Research Institute (SARI);

P. O. Box 6024;

Arusha, Tanzania.

Email: prmatowo@yahoo.com

 

Philemon Mushi;

Scientist, Selian Agricultural Research Institute (SARI);

P. O. Box 6024;

Arusha, Tanzania.

Email: ppmushi56@yahoo.com  

Additional information

The technology was validated using on-farm trials. In the firststudy, eight (8) mother trials, (each replicated two times), were conducted inthe districts of Babati, Karatu, Arumeru/ Monduli and Hai districts. Four (4)farmer assessments were conducted in Karatu district and at Mareu in Arumerudistrict. In year two of the project, the treatments were repeated in the sameplots to see the effects of the legume with stage two repeated. Data for twoyears was combined and analyzed. The mother trials in each location were composedof Situka-1 and Vumilia K-1, each planted (i) under sub-optimum fertilizer rate,(ii) suboptimum  fertilizer rateintercropped with Dolichos lablab,and (iii) optimum fertilizer rate intercropped with Dolichos lablab

 

Each of the six (6) treatments was planted in a plot size of six(6) rows, each being six (6) meters long. The treatment plots were harvestedand grain yield and biomass data for all the crops was collected and subjectedto statistical analysis. From each agro-ecological zone/district, two (2)villages were selected as trial sites. In each site one farmer or school plotwas identified and a set of six (6) treatments were tested under legumeoptions. In the same village; another group of 15 farmers were each allowed toevaluate two (2) out of the six (6) treatments under their own managementpractices. Hence the 15 farmers together were treated as five replications. Thedesign reached a total of 120 farmers participating in the treatmentcombinations with at least two (2) treatments each. The extension officersparticipated fully in identification of farmers who could make an impact intechnology adoption as early adopters. Farmers and extension staff jointlymanaged the baby trials, whereas scientists from SARI made regular visits, andpaid more attention to the mother trial (under good management) with six (6)treatments. Data on yields, plant stand, plant height and other parameters ofinterest was collected on various treatments.


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