Organic agriculture is gaining momentum in the Philippines as consumers become more health- and environment-conscious. This study investigated soil fertility based on soil chemistry and biological properties of organi...Organic agriculture is gaining momentum in the Philippines as consumers become more health- and environment-conscious. This study investigated soil fertility based on soil chemistry and biological properties of organic vegetable farms in Sariaya, Quezon Province and Los Baños, Laguna Province, with the aim of developing organic agriculture in the Philippines. We utilized the SOFIX (Soil Fertility Index) technology, which is designed to evaluate soil fertility by focusing on the activity and diversity of microbial communities in the soil. This technology provides a scientific assessment of soil health, aiming to contribute to sustainable agriculture and environmental conservation. Soil fertility parameters from four different farms cultivating outdoor organic vegetables were below the recommended values for organic production. Essential macronutrients like nitrogen, phosphorus, and potassium and total carbon content, which is indicative of soil organic matter, were insufficient. Bacterial biomass for soil organic matter decomposition, and nitrogen and phosphorus circulation was inadequate. These results indicated that organic plots lack the fertility needed for optimal organic crop growth. The poor fertility of these organic plots could be attributed to their recent shift from conventional cultivation, which used synthetic pesticides and chemical fertilizers, to organic cultivation approximately seven years ago. This shift may harm soil microorganisms, leading to decreased fertility, nutrient availability and hindering the ability to sustain organic production. Overall, the findings of this case study emphasize the significant soil fertility challenges on organic vegetable farms. Therefore, farmers and agricultural practitioners must adopt appropriate soil management practices to improve soil fertility, microbial populations, nutrient availability, and overall soil health for successful organic production.展开更多
Dianchi Lake is one of the lakes with the richest phosphorus source in the world, in which the P2O5 content in the bottom sediments reaches averagely 0.51 wt % and maximally 1.92%. Studies indicate that this: extremel...Dianchi Lake is one of the lakes with the richest phosphorus source in the world, in which the P2O5 content in the bottom sediments reaches averagely 0.51 wt % and maximally 1.92%. Studies indicate that this: extremely P-rich state is attributed mainly to the large volume (as high as hundred thousands of tons) of phosphatic matter coming into the lake as many rivers feeding the lake pass through a vast area of phosphate-mining districts, which then undergo weathering and particularly some human activities, including waste water discharge. When phosphatic matter enters the lake, its grained parts are firstly decomposed by phosphorus-decomposing bacteria, and finally accumulated in some geographically special parts of the lake, such as a bay area where water flow is much more slower than elsewhere in the lake. With the involvement of phosphorus-concentrating bacteria, the accumulated phosphates in the bottom sludge ultimately form phosphate minerals through deep-burial diagenesis.展开更多
The effective utilization of steel slag, a byproduct produced in large quantities from the steel refining process, is an important issue. Because steel slag contains abundant mineral components, the effects of steel s...The effective utilization of steel slag, a byproduct produced in large quantities from the steel refining process, is an important issue. Because steel slag contains abundant mineral components, the effects of steel slag on soil bacterial biomass and plant mineral uptake were analyzed in this study. The soil pH increased in proportion to the amount of steel slag added. A lower concentration (0.2% to 1%) of steel slag addition did not change the bacterial biomass. However, a higher concentration of steel slag (above 1%) had a negative effect on bacterial biomass. A lower amount of steel slag (0.2% to 1%) addition in soil leads to increased mineral (Ca, Mg, and Fe) uptake and plant growth in Brassica rapa var. periviridis and Spinacia oleracea L. However, mineral uptake by the plants decreased when a large amount of steel slag (above 1%) was added to the soil. Low concentrations of steel slag (0.2% to 1%) in soil had positive effects on plant growth, mineral uptake of plants, and bacterial biomass.展开更多
文摘Organic agriculture is gaining momentum in the Philippines as consumers become more health- and environment-conscious. This study investigated soil fertility based on soil chemistry and biological properties of organic vegetable farms in Sariaya, Quezon Province and Los Baños, Laguna Province, with the aim of developing organic agriculture in the Philippines. We utilized the SOFIX (Soil Fertility Index) technology, which is designed to evaluate soil fertility by focusing on the activity and diversity of microbial communities in the soil. This technology provides a scientific assessment of soil health, aiming to contribute to sustainable agriculture and environmental conservation. Soil fertility parameters from four different farms cultivating outdoor organic vegetables were below the recommended values for organic production. Essential macronutrients like nitrogen, phosphorus, and potassium and total carbon content, which is indicative of soil organic matter, were insufficient. Bacterial biomass for soil organic matter decomposition, and nitrogen and phosphorus circulation was inadequate. These results indicated that organic plots lack the fertility needed for optimal organic crop growth. The poor fertility of these organic plots could be attributed to their recent shift from conventional cultivation, which used synthetic pesticides and chemical fertilizers, to organic cultivation approximately seven years ago. This shift may harm soil microorganisms, leading to decreased fertility, nutrient availability and hindering the ability to sustain organic production. Overall, the findings of this case study emphasize the significant soil fertility challenges on organic vegetable farms. Therefore, farmers and agricultural practitioners must adopt appropriate soil management practices to improve soil fertility, microbial populations, nutrient availability, and overall soil health for successful organic production.
基金The present study is part of the results of a project(No.4987204)granted by the National Natural Science Foundation of China.
文摘Dianchi Lake is one of the lakes with the richest phosphorus source in the world, in which the P2O5 content in the bottom sediments reaches averagely 0.51 wt % and maximally 1.92%. Studies indicate that this: extremely P-rich state is attributed mainly to the large volume (as high as hundred thousands of tons) of phosphatic matter coming into the lake as many rivers feeding the lake pass through a vast area of phosphate-mining districts, which then undergo weathering and particularly some human activities, including waste water discharge. When phosphatic matter enters the lake, its grained parts are firstly decomposed by phosphorus-decomposing bacteria, and finally accumulated in some geographically special parts of the lake, such as a bay area where water flow is much more slower than elsewhere in the lake. With the involvement of phosphorus-concentrating bacteria, the accumulated phosphates in the bottom sludge ultimately form phosphate minerals through deep-burial diagenesis.
文摘The effective utilization of steel slag, a byproduct produced in large quantities from the steel refining process, is an important issue. Because steel slag contains abundant mineral components, the effects of steel slag on soil bacterial biomass and plant mineral uptake were analyzed in this study. The soil pH increased in proportion to the amount of steel slag added. A lower concentration (0.2% to 1%) of steel slag addition did not change the bacterial biomass. However, a higher concentration of steel slag (above 1%) had a negative effect on bacterial biomass. A lower amount of steel slag (0.2% to 1%) addition in soil leads to increased mineral (Ca, Mg, and Fe) uptake and plant growth in Brassica rapa var. periviridis and Spinacia oleracea L. However, mineral uptake by the plants decreased when a large amount of steel slag (above 1%) was added to the soil. Low concentrations of steel slag (0.2% to 1%) in soil had positive effects on plant growth, mineral uptake of plants, and bacterial biomass.
