1599 Slices
Medium 9781780645681

10 How to Make Conservation Agriculture EverGreen

Kassam, A.H. CABI PDF


How to Make Conservation

Agriculture EverGreen

Dennis P. Garrity*

World Agroforestry Centre, Nairobi, Kenya

10.1  Introduction

After decades of research, and the sustained efforts of many pioneering farmers, the concept of Conservation Agriculture (CA) has been steadily expanding (Kassam et al., 2015). Globally, more than 155 million hectares of annual cropland are now managed under zero-tillage CA systems. Meanwhile, worldwide concerns about the potentially devastating effects of climate change on food production continue to intensify. CA has been highlighted as an important component of climate-smart agriculture (CSA) (FAO, 2013;

Lipper et al., 2014).

Investments in CA in the developing world are increasing. However, the uptake of CA in Africa, and in the rainfed upland areas of Asia, has been quite modest so far. Evidence from research, and from widespread indigenous practice, indicates that successful CA systems for tropical smallholders benefit substantially from the integration of trees into these systems (Garrity et al.,

See All Chapters
Medium 9788131807484


Mohan Sen Laxmi Publications PDF


Mac hine T ools




A machine tool is a machine for making components by removing material from the workpiece by using a cutting tool. Machine tools are capable of producing themselves therefore the machine tools are often referred to as mother machine. In the manufacturing processes, machine tools are the most versatile and almost any product can be produced with them. The machine tools should able to fulfill the following requirements:

Requirements of a machine tool

The machine tool should be able to produce consistently the components of specified shape and size, dimensional accuracy and surface finish. These features depend upon the rigidity of the machine elements.

Machine tool should be able to provide the flexibility of machining the material at various cutting speeds and at different material removal rates.

The machine tools should be ergonomically designed so as to enable the operator to setup and control the machine without any problems.


See All Chapters
Medium 9788131806135


Mahesh M. Rathore Laxmi Publications PDF


External Flow

8.1. Laminar Flow Over a Flat Plate—Approximate analysis of momentum equation—Approximate analysis of energy equation. 8.2. Reynolds

Colburn Analogy : Momentum and Heat Transfer Analogy for Laminar Flow Over Flat Plate. 8.3. Turbulent Flow Over a Flat Plate.

8.4. Combined Laminar and Turbulent Flow. 8.5. Flow Across Cylinders and Spheres—Drag coefficient—Heat transfer coefficient.

8.6. Summary—Review Questions—Problems—References and Suggested Reading.

When a fluid flows over a body such as plate, cylinder, sphere etc., it is regarded as an external flow. In such a flow, the boundary layer develops freely without any constraints imposed by adjacent surfaces. Accordingly, the region of flow, outside the boundary layer in which the velocity and temperature gradients are negligible is called the free stream region.

In an external flow forced convection, the relative motion between the fluid and the surface is maintained by external means such as a fan or a pump and not by buoyancy forces due to temperature gradients as in natural convection.

See All Chapters
Medium 9781855206786

Chapter 5: Suspension and Steering

Andrew Everett Brooklands Books ePub

These shafts contain two universal joints and a rubber flexible disc coupling and most are getting a bit ragged now. Like a prop-shaft front coupling, the disc is made by SGF Jurid of nylon-reinforced rubber. Eventually the rubber perishes and can break, leading to very vague steering. Control is maintained, but only just. You have two options when this happens. The expensive one is a new shaft assembly from BMW. The cheap option, costing about six pints of beer and two hours work, is an SGF coupling repair kit containing a new rubber disc and four nuts and bolts. The repair disc differs from the original because it is fitted with steel sleeves for the bolts.

Taking off the shaft can be difficult. Remove the top and bottom pinch bolts and nuts, wedge an old screwdriver into the expansion slots in the top and bottom joint and give it a good hammering. This loosens the joint from the rack and the column. Now soak both joints in penetrating oil and go and make a cup of tea. After five or ten minutes go back and get the shaft off. Using a hammer and a long bar, drive the shaft down onto the rack but go carefully hit it too hard and you might damage an expensive steering rack. Plenty of penetrating oil and moderate taps are all that is required. After a while, the shaft will drop away from the column. From underneath, tap the shaft back up off the rack and free.

See All Chapters
Medium 9781780640884

5 Water Use in Agroecosystems

Boelee, E. CABI PDF


Water Use in Agroecosystems

Renate Fleiner,1* Delia Grace,2 Petina L. Pert,3 Prem Bindraban,4

Rebecca E. Tharme,5 Eline Boelee,6 Gareth J. Lloyd,7 Louise Korsgaard,7

Nishadi Eriyagama8 and David Molden1


Centre for Integrated Mountain Development (ICIMOD), Kathmandu,

Nepal; 2International Livestock Research Institute (ILRI), Nairobi, Kenya;

3Commonwealth Scientific and Industrial Research Organisation (CSIRO), Cairns,

Queensland, Australia; 4World Soil Information (ISRIC) and Plant Research

International, Wageningen, the Netherlands; 5The Nature Conservancy (TNC), Buxton,

UK; 6Water Health, Hollandsche Rading, the Netherlands; 7UNEP–DHI Centre for

Water and Environment, Hørsholm, Denmark; 8International Water Management

Institute (IWMI), Colombo, Sri Lanka


The integrated role of water in ecosystems and, in particular, in agroecosystems, as well as the multiple uses of water – across various sectors that have increasing demands, have been widely recognized. But regions and institutions are still struggling to resolve issues around water – be it scarcity, accessibility or degradation. Mostly, they are caught in conventional institutional and policy frameworks that have been set up based more on sectoral than on cross-sectoral principles, thus preventing them from achieving the ultimate goal of sustainability. This chapter analyses the current and future challenges related to water availability and water use for agriculture from this perspective. It looks at water quantity and quality, water infrastructure, and related governance and institutional aspects, using case studies from basins in different geographic regions.

See All Chapters

See All Slices