Status, priorities and needs for sustainable soil management in

Transcription

1 Status, priorities and needs for sustainable soil management in Zambia Stalin Sichinga Zambia Agriculture Research a b a g cu tu e esea c Institute

2 Introduction Zambia has an area of 750,000 km 2 with about 13.9 million people and ample land resources 0ut of 9 million ha cultivable land, only 14 is cropped in any year About of the land area is covered by natural forest and 6 of Zambia s land surface is covered by water.

3 Chililabombwe Chingola Kalulushi Mufulira Kitwe Luans hya Ndola Agro-ecological regions and soil distribution The country is classified into three agro-ecological regions based on soil types, rainfall, and other climatic conditions Agro-Ecological Regions Agro-ecological Region I Annual rainfall is <750mm N Chiengi Kaputa Mpulungu W E Nchelenge Mbala Mporokoso S Kawambwa Mungwi Scale 1: 2,500,000 Mwense Luwingu Kasama Chinsali Mwinilunga Solwezi Chavuma Kabompo Zambezi Mufumbwe Kasempa Lukulu Kaoma Kalabo Mongu Senanga Sesheke Shangombo Mumbwa Itezhi-Tezhi Namwala Kazungula Kalomo Livingstone Kilometers Lufwanyama Mansa Milenge Masaiti Chilubi Samfya Mpika Serenje Mambwe Nakonde Isoka Chama Lundazi Mpongwe Chipata Petauke Katete Mkushi Chadiza Kapiri Mposhi Nyimba Kabwe Chibombo Chongwe Lusaka Urban Luangwa Kafue Mazabuka Monze Siavonga Gwembe Choma Sinazongwe LEGEND Regions I IIa IIb III KEY District boundary December 2002 The region contains a diversity of soil types ranging from slightly acidic Nitosols to alkaline Luvisols with pockets of Vertisols, Arenosols, Leptosols and, Solonetz.

4 The physical limitations of region I soils Hazards to erosion, limited i soil depth in the hills and escarpment zones, presence of hardpans in the pan dambo areas, poor workability in the cracking clay soils, problems of crusting in most parts of the Southern province, low water-holding capacities and the problem of wetness in the valley dambos, plains and swamps. Chemical limitations of region I soils Some soils have salt content of which sodium is predominant, causing problems of sodicity and salinity, acidity and low nutrient reserves and retention capacity.

5 Chililabombwe Chingola Kalulushi Mufulira Kitwe Luans hya Ndola Agro-ecological Region II Rainfall mm. Subdivided based on differences in soil types.. Agro-Ecological Regions N W E S Scale 1: 2,500,000 Chiengi Kaputa Mpulungu Nchelenge Mbala Mporokoso Kawambwa Mungwi Mwense Luwingu Kasama Nakonde Isoka Sub-region IIa, soils are largely classified as Lixisols, Luvisols, Alisols, Acrisols, Leptosols and Vertisols Mwinilunga Chavuma Kabompo Zambezi Mufumbwe Lukulu Kaoma Kalabo Mongu Senanga Sesheke Shangombo Kazungula Kalomo Livingstone Chinsali Chilubi Mansa Chama Samfya Milenge Mpika Solwezi Lundazi Lufwanyama Serenje Mambwe Masaiti Mpongwe Chipata Kasempa Petauke Katete Kapiri Mposhi Mkushi Chadiza Nyimba Kabwe Mumbwa Chibombo Chongwe Lusaka Urban Luangwa Itezhi-Tezhi Kafue Namwala Mazabuka Monze Siavonga Gwembe Choma Sinazongwe LEGEND Regions I IIa IIb III KEY District boundary Kilometers December 2002 These are some of the best agricultural soils in Zambia and they host much of the country s commercial farming sector

6 Chililabombwe Chi ngola Kalulushi Mufulira Kitwe Luanshya Ndola Agro-ecological Region II Rainfall mm. Subdivided based on differences in soil types. Sub-region IIb N W E S Scale 1: 2,500,000 Agro-Ecological Regions Chiengi Kaputa Mpulungu Nchelenge Mbala Nakonde Mporokoso Kawambwa Mungwi Isoka Mwense Luwingu Kasama Contains a range of Arenosols, Gleysols, Histosls, and Podzols Chinsali Chilubi Mansa Chama Samfya Milenge Mpika Mwinilunga Solwezi Lundazi Lufwanyama Chavuma Serenje Mambwe Kabompo Masaiti Zambezi Mpongwe Mufumbwe Chipata Kasempa Petauke Katete Kapiri Mposhi Mkushi Chadiza Nyimba Kabwe Lukulu Kaoma Mumbwa Chibombo Kalabo Mongu Chongwe Lusaka Urban Luangwa Itezhi-Tezhi Kafue Namwala Mazabuka Senanga Monze Siavonga Sesheke Gwembe Shangombo Choma Kazungula Kalomo Livingstone Kilometers Sinazongwe LEGEND Regions I IIa IIb III KEY District boundary December 2002

7 The physical limitations of region II soils low water holding capacity, shallow rooting depth, rapid physical deterioration, erosion hazard and poor workability Chemical limitations of region II soils low nutrient reserves and retention capacity, low calcium, magnesium and phosphorous, low organic matter content and high acidity in some pockets

8 Chililabombwe Chingola Ka lulushi Mufulira Ki twe Luanshya Ndola Agro-ecological Region III High rainfall region of Zambia >1000mm per annum. Agro-Ecological Regions Predominant soils: Acrisols, and some Ferralsols developed under conditions of high leaching intensity N Chiengi Kaputa Mpulungu W E Nchelenge Mbala Nakonde Mporokoso S Kawambwa Mungwi Isoka Scale 1: 2,500,000 Mwinilunga Solwezi Chavuma Kabompo Zambezi Mufumbwe Lukulu Kaoma Kalabo Mongu Senanga Sesheke Shangombo Lufwanyama Mwense Luwingu Kasama Chinsali Chilubi Mansa Chama Samfya Milenge Mpika Lundazi Serenje Masaiti Mpongwe Kasempa Kapiri Mposhi Mkushi Nyimba Kabwe Mumbwa Chibombo Chongwe Lusaka Urban Luangwa Itezhi-Tezhi Kafue Namwala Mazabuka Monze Siavonga Gwembe Choma Kazungula Kalomo Livingstone Kilometers Sinazongwe Mambwe Chipata Petauke Katete Chadiza LEGEND Regions I IIa IIb III KEY District boundary December 2002 Soils are characterized by soil acidity, low bases retention capacity, low soil organic matter, low general soil fertility and soil degradation

9 Major Soil group classification Soils of Zambia LEGEND N Soils Types W E Acrisols S Alisols Kasama Arenosols Cambisols Mwansa Ferralsols Fluvisols Solwezi Gleysols Histosols Ndola Kabwe Chipata Leptosols Lixisols Luvisols Nitisols Phaeozems Mongu Lusaka Planosols Podzols KEY Regosols Solonchaks Livingstone Provincial Capital Lakes Solonetz Vertisols Associations Soil Survey Unit, Mt. Makulu April 2003

10

11 Main Challenge of Agriculture Productivity in Zambia The declining soil fertility soil erosion and degradation and little or non- use of manure or chemical fertilizer and the ravages of erratic rainfall. Need to improve and manage soil fertility in Zambia There are several options of positive soil fertility There are several options of positive soil fertility management practices available to farmers

12 Summary of soil fertility management practices in Zambia Technology Category Practice Advantage Reduction in fertilizer use, Cultural Crop rotation Practices Agro forestry improved po fallow Legumes after cereals 2-3 year fallow phase with tree species like Gliricidia, Acacia, Leucaena, Sesbania, Tephrosia, etc Improved soil fertility, pest and disease control, weed control (e.g. striga) Improve soil fertility, control and avoid soil erosion, cost effective or reduce the use of chemical fertilizer, improve soil structure

13 Summary of soil fertility management practices in Zambia Technology Category Practice Advantage Cultural l Practices Green manure crop fallows Velvet beans and Sun hemp either incorporated or left on the surface Improve soil structure and fertility, leading to vigorous growth of the following crop and reduce erosion Compost manure practices Mixed plant residues, animal dung, earth / soil materials, wood ash, water Improves soil structure, reduce erosion and improves water and nutrient holding capacity of the soil

14 Summary of soil fertility management practices in Zambia Technology Category Practice Advantage Erosion control practices Conservation tillage Ripping, basins and minimum tillage Erosion control and rain water infiltration Contour conservation Vertiver grass Liming Dolomitic (more magnesium than calcium) or calcitic (more calcium than magnesium) lime Reduces soil acidity, make nutrients readily available for crop uptake and eliminates i aluminium i toxicity

15 Summary of soil fertility management practices in Zambia Technology Category Practice Advantage Inoculum Rhizobia inoculum Enhances biological nitrogen fixation in legumes and increases yields Fertilizers* Basal and top dressing fertilizers Supply the nutrients needed for enhanced crop production *Wherever possible, it is recommended that farmers should combine organic and inorganic nutrient sources for sustainable crop production

16 Thank You for your attention