No abstract

No abstract

No abstract

Changing environmental conditions can affect plant growth by influencing water and nutrient transport and photosynthesis. Plant physiological responses under changing environmental conditions can be non-destructively monitored using electrodes as plant induced electrical signal (PIES). Objective of the study was to monitor PIES in response to increased CO 2 and decreased photosynthetic photon flux density (PPFD). The PIES increased during day time when transpiration and photosynthesis occurs and monitored CO 2 concentration was negatively correlated to the PIES. Enhanced CO 2 concentration slightly reduced PIES, but the effect of increased CO 2 was limited by light intensity. The effect of reduced PPFD was not appeared immediately because water and nutrient transport was not promptly affected by the light. The study was conducted to evaluate short-term effect of increasing CO 2 and decreasing PPFD, hence proline content and chlorophyll fluorescence was not significantly affected by the conditions.

The imbalance of nutrient and water supply can negatively affect crop productivity and environment. Therefore, it is necessary to monitor nutrient and water status of soil and precision management of the soil is required. Soil water content can be measured using sensors such as frequency domain reflectometry (FDR) and time domain reflectometry (TDR). Tensiometer was commonly used to determine irrigation timing and amount to supply water. Organic matter in the soil can be measured using a near infrared spectrometer (NIR) sensor, which showed good correlation with soil organic matter contents. On-the-go pH sensor was used for pH mapping of soil with high resolution. Generally, organic matter and pH sensors are less used for soil based smart farm system than soil moisture sensors, but used for the characterization of soil. There are no available sensors to monitor nutrient levels in soil directly. To use ion selective electrodes, soil solution should be extracted. Instead, monitoring soil EC can be used to manage nutrients in soil since the soil EC is related to nutrients in soil solution. However, EC and nutrient availability in soil are affected by various factors such as soil water content, temperature and soil texture. Therefore, calibration of EC based on soil texture, CEC, soil organic matter, and etc. is required. Recent researches for soil based smart farm focused on wireless sensors, plant wearable sensors, and intelligent agriculture systems. Combined monitoring of environmental conditions and plant biometric information will achieve smart and precision agriculture.