1、Nitrogen and phosphorus changes and optimal drainage time of flooded

This study was conducted to examine the changes of nitrogen and phosphorus of a flooded paddy water system after fertilizer application and at each growth stage so as to obtain the optimal drainage time at each growth stage.

2、Nitrogen and phosphorus losses from paddy fields and the yield of rice

Abstract The assessment and control of losses of nitrogen (N) and phosphorus (P) from paddy fields is critical to improve the quality of water and atmosphere on earth.

3、Effects of Different Fertilizer Types on Nitrogen Loss in Paddy Field

This study applied a field experiment to investigate the effects of different fertilizer types on nitrogen loss in a paddy field. The fertilizer types included control (CK), conventional formula fertilizer (CT), partial replacement of organic fertilizers to chemical fertilizers (BS) and carbon-based fertilizer (CB). The results showed that the ...

Nitrogen and phosphorus leaching losses from paddy fields with

Most of the existing reports on N and P leaching losses from paddy fields are based on fertilizer rates, fertilizer types, patterns of fertilizer application or soil types under flooding condition, and water regimes as midseason drainage.

Effects of Different Types of Water and Nitrogen Fertilizer Management

The results of this study provide an important basis for guiding high yield, water-savings, and emission reduction of paddy fields in cold regions.

Effects of nitrogen fertilizer sources and tillage practices on

However, relatively few studies have reported the impacts of different N fertilizer types on the NEEB in paddy fields. Moreover, the combined effects of N fertilizers and tillage practices on the GWP and NEEB in paddy fields have not been well elucidated.

Long

Abstract Yuanyang terrace paddy soils in subtropical regions of Southwest China are characterized by thousands of years of flooding and low input of chemical fertilizers, but the nitrogen (N) fertilizer use efficiency is generally higher and the N loss is frequently lower.

Effects of biofertilizers on nonsymbiotic nitrogen fixation in

In this study, two representative paddy soils (HH and SH) in China with significant differences in their nitrogen fixation activities and physicochemical properties were selected.

Effects of Different Fertilization Modes on Nitrogen and Phosphorus

In the field plot experiment of the Chaohu Paihe small watershed, four treatments, including T1 (conventional compound fertilizer), T2 (bio-organic fertilizer replacing 30% nitrogen fertilizer), T3(loss-of-control fertilizer replacing 30% nitrogen fertilizer), and T4 (bio-organic fertilizer and loss-of-control fertilizer replacing 15% nitrogen ...

Microsoft Word

This study investigated the effect of applying different types of fertilizers (no fertilizer, conventional chemical fertilizer, combinations of organic and inorganic fertilizers, and a slow-release fertilizer) in paddy fields on N losses in surface runoff water.

Flooded paddy fields are unsuitable for applying nitrogen fertilizers with high nitrogen content. This is primarily because nitrogen in flooded conditions readily decomposes, leading to nitrogen loss. Such losses not only waste fertilizer but may also cause environmental pollution.

Key Reasons:

1. Nitrogen Loss and Environmental Risks: Nitrogen fertilizers play a critical role in crop growth, but when applied to flooded paddy fields, the nitrogen compounds dissolve and disperse in water, resulting in significant nutrient loss. This increases the risk of eutrophication in water bodies, disrupting aquatic ecosystems.
2. Toxic Gas Emission: The decomposition of nitrogen fertilizers releases toxic gases like ammonia, which harm human health and agricultural productivity.

Alternatives and Precautions:

• Low-Nitrogen or Nitrogen-Free Fertilizers: Opt for fertilizers with reduced or no nitrogen content to minimize nutrient loss.
• Avoid Other High-Risk Fertilizers: Phosphate and potassium fertilizers may leach into rivers, exacerbating eutrophication. Organic fertilizers (e.g., animal manure) should be applied under dry conditions to prevent odorous fermentation.

Best Practices for Fertilization in Flooded Fields:

1. Timing: Avoid fertilizing during rainy periods. Apply fertilizers on sunny mornings or evenings to reduce runoff.
2. Fertilizer Selection: Choose organic fertilizers over synthetic ones to enhance soil nutrient retention and crop quality.
3. Dosage Control: Adjust fertilizer amounts and concentrations based on crop stages and soil fertility. Excessive use leads to salt buildup, while insufficient application hinders growth.
4. Field Management: Remove weeds and pests promptly, maintain clear drainage systems, and prevent stagnant water to reduce nutrient loss.
5. Soil Testing: Regularly monitor soil nutrients through testing to guide scientific fertilization.

High-nitrogen fertilizers are unsuitable for flooded paddy fields due to nitrogen loss and environmental hazards. Prioritize low-nitrogen or nitrogen-free options, adopt sustainable practices, and integrate soil monitoring to balance crop nutrition with ecological protection.