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MITIGATION OF SOIL ACIDITY AND FERTILITY DECLINE CHALLENGES FOR SUSTAINABLE LIVELIHOOD IMPROVEMENT: EVIDENCE FROM SOUTHER REGION OF ETHIOPIA. By Wassie Haile & Shiferaw Boke Awassa Agricultural Research Center. INTRODUCTION. Soil Acidity
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MITIGATION OF SOIL ACIDITY AND FERTILITY DECLINE CHALLENGES FOR SUSTAINABLE LIVELIHOOD IMPROVEMENT:EVIDENCE FROM SOUTHER REGION OF ETHIOPIA By WassieHaile & ShiferawBoke Awassa Agricultural Research Center
INTRODUCTION Soil Acidity • Soil acidity/Al toxicity is a serious threat to crop production in most highland of Ethiopia • Currently about 40% of arable lands are affected • Expanding both in scope and magnitude
Soil acidity impairs root devt. there by reduce water and Nutrient uptake • Acid soils are deficient in K, Ca, Mg, Mo Ultimately reduce crop growth and yield • Cause • Parent forming material • Leaching of Basic cations • Use of acid forming fertilizers (Urea&DAP)
Barely Field Severely damaged by soil acidity At Hagereselam
In SNNPR Highland of Sidama, Gamogofa, Gembata, Guragie, Hadya and south west Ethiopia are areas affected by soil acidity • Methods of overcoming soil acidity -Liming -organic amendments -Tolerant crops
Soil fertility Decline • Declining soil fertility is an other big challenge to crop pron. • Mining of soil nutrients due to continuous cultivation, abandoning of fallowing, crop rotation, reduced manure app., erosion coupled with low inherent soil fertility are the main causes. • But unlimited rise in population is the core cause
To over come the problem appl. Of inorganic fertilizers have been started some four decades ago. • Appreciable in the yields of several crops were obtained Because of immediate availability of nutrients to crops - ease of application -Low price in the past -Immediate visible impact and others, their adoption was very fast -However now it is understood that inorganic fertilizers are not sustainable means of overcoming soil fertility decline Why? -Increasing cost -some of the acidify soil and then promote cation losses -cause the depletion of other soil nutrient -Pollution of the environment -Reduced fertilizer recovery efficiency by crops
Alternative • Organic nutrient sources • FMY, Compost, green manure • FMY and to some extent compost is an age old practice and excellent ways of soil fertility maintenance • Leguminous cover crops and trees are excellent nutrient sources • Green manuring and biomass trasnfer of leguminous crops are organic fertilizers proven to be excellent.
In addition to being nutrient sources organic fertilizers improve the physico-chemical and biological characteristics of the soil, increase WHC, CEC etc.. However, ON sources have also problem • -vary in quality • - some Org. sources are poor in specific essential elements • - take time to decompose so on • Green manures and trees legumes are exotic to Ethiopia, difficult to get them adopted
So What? • Integrated application of organic- inorganic nutrient sources the best way of overcoming the short comings of both sources • There are many research findings indicating the superiority of both sources applied than alone in improving soil fertility for enhanced crop yield • There is a need to identify nutrient rich Og from local sources
I. FARMERS' COPPING STRATEGIES CHENCHA • Farmers of Chencha said they used to apply fertilizers in the far past but now stopped • They now relay on FMY for out field prn • If their soil become completely unproductive they plant it with lupine • Use falling litters of Croton macrostaches (Locally, Anka), Hagenia, Erythrina
Hagereselam • They let the weeds grow on their field during short rainy season • Then the plow under the weeds 3times before planting barely during meher • they use minimum tillage • plant lupine • Acid tolerant variety (Hulla)
II. RESEARCH FINDINGS ON SOIL ACIDITY AND FERTILITY MANAGEMENT TECHNIQUES FROM SOUTHERN ETHIOPIA 1. Effect of integrated application of organic – inorganic on the tuber yield of potato in acid soils of Chencha Experiment I. The result of organic-inorganic fertilizer application on tuber yield of potato is shown in Table 1.
Application of NP did not significantly increase the yield of potato compared with Control • But addition of NP including K increased the yield significantly, suggesting that K is critically deficient at Chencha • NPK increased tuber yield by 363 and 392% over NP and Control • The only fertilizers are to be used balanced appl. Of NPK is a must • Yield was further increased with App. Of NPK + FMY • 567% increase
NPK+ FYM gave the highest net Benefit (52616birr) and MRR (2350)
Experiment II NP app. Decreased The yield by 10% NPK + FMY Increased The yield significantly
2. The effect of integrated applications of organic-inorganic fertilizers on the yield of barley at acid soils of Chencha
3. Exploitation of locally available Organic nutrient sources for soil fertility improvement So far limited efforts were Made to introduce exotic Plant species to serve as Organic nutrient sources, But little adoption by farmers At the same time no attempt Was made to exploit organic Fertilizers from local sources Erythrina bruci is nutrient rich Locally available multipurpose Tree that can serve as Orga Nic fertilizer N = 4.83%, P =0.38% K = 2.24%
Lsd(0.05)= 3.7 • Appl. Of E. bruci at • 5 and 10t/ha increased • The grain yield by 86 and 134% • N23P40 + 10t/ha • Increased the yield by 189% Figure 2. The of effect transferred on grain yield of wheat
4. The effect of liming and fertilizers on tuber yield of Potato at acidic soils of Chencha • Lime appl. alone did • Not improve tuber yield • Implying high depletion of Nutrient • N110P40K100 + 3.5t lime increased the tuber Yield by 418% • Has to be applied together with fert.
Policy Implications Application of lime alone is not a solution to soil acidity Even it could be dangerous unless it is with organic and/or inorganic fertilizers. Potassium is now proved to be deficient in some acidic soils of Ethiopia, thus K-fertilizers should be imported. Application of NP in the form of urea and DAP on acid soils shown to aggravate soil acidity so alternative none acidifying fertilizers. should be imported and demonstrated. Thus to make acidic soils sustainably productive strict production condition or policy should be set. Promotion of INSF is important.
SOIL IS OUR SOUL SO LET US SAVE OUR SOIL!!! THANK YOU