Conservation agriculture Tanzania_casestudy.pdf - Sokoine ...

slasher, machete and billhook (nyengo) were recommended for managing soil cover.The jab planter and direct seeder were initially imported from the Fitarelli companyin Brazil. The Zambia-designed rippers and ripper planters were procured fromSEAZ Agricultural Equipment Ltd.The initial research trial in 1998 compared rainwater capture and storage featuresof ridges, tied ridges, opening planting furrows with the ripper, and leaving the restof the land untilled with conventional mouldboard ploughing. Tilling was startedtwo weeks before the expected rainfall. Planting was done before or at the beginningof rainfall. Weeds were managed using the ridger in ridged plots, tie ridger in tiedridged plots, the contact herbicide Gramoxone in ripped plots and the hand hoe inthe ploughed plots. These treatments were repeated for the second weeding, exceptthe herbicide was replaced with ox cultivation. For the first three years tied ridgesproduced the highest yield, followed by ridges, conventional ploughing and with theripper last. Due to excessive labour needed for ridging and tied ridging, the farmerschose the plough, as evaluated by a pair-ranking matrix.An obvious weakness in the package was spraying contact herbicide in thesefarmer-managed trials. The herbicide was usually procured late and inexperienceduse resulted in killing the crop. Gramoxone was abandoned for first weeding. Thenegative experiences included no money to buy the herbicide when needed, dilutionleading to low effectiveness, and inexperienced use.When similar techniques were evaluated in 2001, under the Tanzania AgriculturalResearch Project Phase II and Sokoine University of Agriculture (TARP II SUA),ridges were replaced with a ripper planter and it was decided to do away withcontact herbicides to manage weeds. The 12 households of Wanging’ombe villagewere dropped, and five new villages, Kisilo and Mayale in Njombe District andMatai, Nkundi and Sandulula in Sumbawanga District, Rukwa Region, wereselected. Ridges and tied ridges performed better compared with ripping andploughing in years of moderate-to-good rainfall, but poorer compared with rippingwhen rainfall was below moderate. Furthermore, tied ridges needed three timesthe labour of ripping. Maize yield was consistently superior to that from othertreatments (see table 7).Jab planters and direct seeders were used in the latest conservation agricultureresearch and development efforts under Soil Fertility Initiative of MAFS introducedin 2001 and also the MAFS- and FAO-supported Technical Cooperation Projectof the United Republic of Tanzania (URT) 3002 initiated in 2004. Under the SoilFertility Initiative, four new villages of Mapogoro and Njelenje in Mbeya District,two new villages of Kanamalenga and Kisilo in Njombe District and one newfarmer group were added in Wanging’ombe village. In addition to conservationagriculture, specific themes were cover crops, direct seeding equipment, agroforestryand breaking hardpans. The project for Mbeya District targeted 250 households innine villages, concentrating on direct seeding and cover crops.Jab planters worked best in dry seeding in sandy soils or when soil moisture waslow. They did not clog. The seeds and fertilizer were planted and germinatedalmost perfectly. They performed poorly when soils were too wet or under thick soilcover. In a matrix ranking of the planting methods, farmers preferred the ripper.Mbeya District 123