Sustainability index was calculated to assess soil quality under the influence of different fertilizer management practices. It is based on the area of the triangle in which nutrient index, microbial index and crop index of soil represented the three vertices of a triangle. Nutrient index reflected the nutrient status of soil and was calculated from the measurements of various soil chemical parameters. Microbial index was calculated by determining various soil microbial and biochemical activities and crop index by measuring of crop yield parameters. Eighteen soil indicators were determined to assess nutrient index, microbial index and crop index in order to compare the effect of different sources of nutrients such as green manure, farmyard manure and chemical fertilizer in a rice/corn– wheat rotation. The indices were applied to assess the sustainability of five field experiments with respect to the different fertilizer treatments. The long-term application of organic manures in rice/corn–wheat cropping system increased the index value because it increased the nutrient index, microbial index and crop index of soils. The use of only chemical fertilizers in the rice–wheat cropping system resulted in poor soil microbial index and crop index. In corn–wheat system, additional application of FYM at 10 t ha−1 before sowing corn made the system more sustainable than application of 100%NPK; the sustainability index values were 2.43 (the highest for this system) and 0.93, respectively.
Crop production systems that require chemical fertilizers, pesticides, machinery for
tillage, and irrigation water are expensive. In countries such as India, they have started
to undermine the water security of future generations, contributing to soil and water
pollution particularly when synthetic pesticides are not used properly. It is true that
agriculture as practiced 100 years ago without modern inputs had lower productivity
than present systems of production. However, many premodern practices, such as the
use of organic manures to enhance soil fertility and of herbal extracts to protect crops,
can be made more efficient by the scientific knowledge that has been gained over
the past century, making crop production more sustainable while still achieving high
This paper analyses food security status in planned and unplanned settlements using Dodoma municipality in Tanzania as case study. Data for the study were collected from a total of 97 households through interviews using structured questionnaire. Both purposive and simple random sampling procedures were used as criteria for sample selection. Ordinary Least Regression Model was used to ascertain social and economic factors significantly influencing food security among households living in planned and unplanned settlements. Estimation was carried out using LIMDEP soft ware. The findings of the study revealed that households living in unplanned settlement are food insecure compared to their counterparts living in planned settlements. The authors concludes that this were partly due to the fact that food availability, food accessibility and nutritional aspects were relatively better in planned settlement than their counterparts in unplanned settlement; and that the situation was partly due to low purchasing power, lack of employment and lack of credits. They finally recommend that there should be improvement of purchasing power; provision of credits; provision of food assistance to vulnerable households; and promotion of diversification of economic activities.