1、Estimation of nitrogen fertilizer requirement for rice crop using

Estimating in-season nitrogen requirement is essential for crop nitrogen management. Critical nitrogen dilution curve is an effective and simple tool for assessment of in-season crop nitrogen requirement. Crop growth stages can play an essential role in quantifying in-season nitrogen requirement.

2、How Much Fertilizer Per Hectare For Rice?

The ideal nitrogen fertilizer rate for rice varies depending on several factors, including soil type, climate, rice variety, and existing nitrogen levels. However, a general guideline is to apply 100-150 kg of nitrogen per hectare.

3、Nutrient Management in Rice Crops

Many farmers apply 0,5 tons of N-P-K 30-10-10 per hectare at the day of sowing/planting (or 20 days later). About 45-60 days after the first application, they apply 0,2-0,3 tons of N-P-K 40-0-0 or 33-0-0 per hectare. Keep in mind that 1 ton = 1000 kg = 2.200 lbs. and 1 hectare = 2,47 acres = 10.000 square meters.

4、Nitrogen Nutrition of Rice Plant

If one wants to make the rice plant follow the type 1 course of nitrogen intake by application of fertilizers, he must attach great importance to the top-dressing of nitrogen fertilizer.

5、Nutritional Summary

Nitrogen affects all parameters contributing to yield (e.g. spikelet number per panicle, percentage of filled spikelets, grain protein content) and, thus, a sufficient N supply is necessary for achieving high yields.

The Best Fertilizer for Rice Crop: Organic, NPK, and

Fertilizer is essential if you want to increase yields. Nitrogen is the most restrictive nutrient for NPK Rice production. Nitrogen is essential for plant height, leaf size, panicle number, and high yield per hectare. Rice requires a lot of nitrogen to make pancakes.

IV.3 Nutrient calculator

For nitrogen, for example, even with good management about half the applied fertilizer (50%) is lost. We said above that the plants need to take up 15 to 20 kg of nitrogen per hectare to produce 1 ton of grain.

Estimating thresholds of nitrogen, phosphorus and potassium fertilizer

In this study, we proposed a method that utilizes allowed ranges of partial nutrient balance and yield to estimate the threshold of nitrogen (N), phosphorus (P), and potassium (K) fertilizer applied to rice (Oryza sativa L.) fields in China.

Cooking and eating quality of rice as affected by nitrogen fertilizers

Abstract The grain filling is the key period for quality formation in rice, which is greatly influenced by nitrogen (N) fertilizer and irrigation management. This study aimed to investigate effects of different N fertilizer rates and irrigation regimes at panicle stage on rice cooking and eating quality.

Arkansas Rice Production Handbook

Nitrogen (N) is required by rice in the largest quantities of any nutrient, and it is typically not only the largest fertilizer input cost but the largest input cost for rice producers.

Rice, as one of the most important food crops globally, has its nitrogen (N) fertilizer requirements during cultivation significantly impacting yield and quality. This article provides a detailed overview of rice’s nitrogen needs, including calculation methods, influencing factors, and recommendations for rational application.

I. Calculation Methods for Nitrogen Requirements

1. Nitrogen Requirement per Unit Area: Typically calculated per hectare (equivalent to a 15m × 15m plot). Depending on rice varieties and soil conditions, nitrogen needs range from tens to hundreds of kilograms per hectare. For example, research by the Chinese Academy of Agricultural Sciences indicates that medium-fertility paddy fields require 20–30 kg of urea per hectare, while high-fertility fields may need over 40 kg.

2. Staged Fertilization: Nitrogen demand varies across two key growth phases:

   • Early stage: Promotes tillering and root development.
   • Late stage: Supports panicle formation and grain filling. Fertilizer amounts differ accordingly.

3. Comprehensive Considerations: Soil fertility, climate, crop density, irrigation, and other factors all influence actual nitrogen needs. Field trials or professional consultations are recommended for precise adjustments.

II. Factors Affecting Nitrogen Requirements

1. Soil Fertility: Indicators such as organic matter, total nitrogen, available phosphorus, and potassium directly affect nitrogen uptake efficiency. Higher soil fertility reduces the relative need for nitrogen fertilizers.

2. Climate: Temperature, rainfall, and sunlight impact nitrogen absorption. For instance:

   • Hot and rainy conditions: Accelerate rice growth, increasing nitrogen demands.
   • Drought or low rainfall: Slow growth reduces nitrogen needs.

3. Rice Variety: Different varieties have varying nitrogen sensitivities. Some low-nitrogen-tolerant varieties maintain high yields with limited fertilizer, while nitrogen-demanding varieties require more. Local climate and soil should guide variety selection.

III. Recommendations for Rational Nitrogen Application

1. Combine Base and Topdressing Fertilizers: Apply nitrogen in two stages:

   • Base fertilizer: Supports early growth.
   • Topdressing: Supplements nutrients during later stages.

2. Timely and Appropriate Application: Adjust timing and dosage based on growth stages and soil tests. Early and mid-season rice generally require more nitrogen than late rice. Weather forecasts and soil analysis should inform decisions.

3. Integrate Organic Fertilizers: Compost, green manure, or other organic inputs improve soil structure and microbial activity, enhancing nitrogen use efficiency. Combining organic and synthetic fertilizers optimizes nutrient balance.

4. Monitor and Adjust: Regularly assess soil fertility and crop health. Calibrate fertilizer plans based on monitoring data to ensure adequate nutrition at all growth stages, maximizing yield and quality.

rice’s nitrogen requirements are shaped by soil, climate, variety, and management practices. Scientific fertilization strategies—tailored to local conditions—ensure efficient nutrient use, sustainable production, and high-quality yields.