abstract the amount of needed fertilizer in agricultural soils depends to the type of crop. absence of enough fertilizer may cause in tensions in plants and consequently result in decrease in amount of product. according to the agricultural literature, soils containing total nitrogen amounts (n %) between 0.1-0.15 percent are considered as soils containing normal amounts of nitrogen. the values...

Tillage practices and nitrogen (N) sources are important factors affecting rice production. Few studies, however, have examined the interactions between tillage practices and N fertilizer sources on NH3 volatilization, nitrogen use efficiency (NUE), and rice grain yield. This study aimed to investigate the effects of N fertilizer sources (no N fertilizer, inorganic N fertilizer, organic N ferti...

• Session 1: Objectives, outcomes, and trade-offs associated with alternative fertilizer promotion programmes. • Session 2: What determines the cost of fertilizer at the farm gate? Cost build-up analysis (Bumb, g p y (IFDC) • Session 3: Fertilizer profitability analysis (Rashid and Jayne, IFPRI/MSU) • Session 4: Experiences and lessons learned with alternative fertilizer promotion efforts (Mino...

Fertilizer application control in reason is the key technology to improve operation quality, reduce fertilizer pollution, and cut down costs of production. A control system of variable rate fertilizer is developed based on microcontroller chip in the paper. The system can automatically control flow dosage by adjusting feed gate opening size and changing hydraulic motor speed of fertilizer conve...

This note demonstrates that a certain class of stochastic problems for determination of optimal fertilizer application rates in the presence of fertilizer carry-over can be simplified to static, certainly equivalent problems. Conditions required for certainty equivalence to hold are: (1) fertilizer carry-over is agronomically equivalent to applied fertilizer; and (2) some addition of fertilizer...

A variable rate fertilizer system was developed for control of fertilizer amount by optical sensor measured NDVI of crop. The paper analyzes the input and output conditions of control system, and designed hardware, algorithm and control of fertilizer, mainly software flow and a feedback control way. In the paper, the variable-rate control system consisted of 6 optical sensors mounted on a boom ...

Precision agriculture is the developing trend of modern agriculture, and the rational utilization of fertilizer is one of the key technologies in the precision agriculture, which needs to fertilize variably according to the crop needs and soil fertility conditions. Thus a fertilizer automated proportioning equipment is developed to Proportion the three fertilizers: Nitrogen fertilizer, Phosphor...

Just after transplanting, the vegetable has difficulty in nutrients uptake. To explore the effect of different fertilization on spring cabbage (Brassica oleracea L. var. capitata) production and fertilizer use efficiencies, this experiment consisting of six treatments was implemented and divided into three groups: 1) no fertilizer (NF) and vegetable planting fertilizer (VPF); 2) conventional fe...