RESUMO
This study aimed to optimize irrigation scheduling for maize (Zea mays L.) using the crop water stress index (CWSI) to improve water use efficiency and yield. The study was conducted in the South farm of the School of Agricultural Sciences, Karunya Institute of Technology and Sciences, Coimbatore during the Kharif and Rabi seasons of 2022. A randomized block design was used with seven treatments, including a control T1 no irrigation). Irrigation at all critical stages (T2) and other five irrigation treatments (T3 to T7) based on different CWSI values ranging from 0.2 to 1.0. Infrared thermometry was used to measure canopy temperatures for estimating the CWSI. The results showed that irrigation at 0.2 CWSI (T3) had a significant positive effect on kernel and stover yield when compared with all the other treatments during both the seasons, with the highest kernel yield of 7138.83 Kg ha-1 and 8014.8 Kg ha-1, stover yield of 11134 Kg ha-1 and 12765 Kg ha-1, respectively and lowest kernel yield of 2267 Kg ha-1 and 2325 Kg ha-1, stover yield of 8156 Kg ha-1 and 6491 Kg ha-1, respectively. The other treatments had intermediate values and did not show any consistent pattern. Irrigation at 0.2 CWSI resulted in the highest water use efficiency (WUE) of 14.7 Kg ha-cm-1 and 17.6 Kg ha-cm-1, and irrigation usage of 31.73% and 22.26% during the Kharif and Rabi seasons of 2022, respectively and the lowest water use efficiency (WUE) of 7.72 Kg ha-cm-1 and 17.6 Kg ha-cm-1 was found in T7 during the Kharif and Rabi seasons of 2022, respectively. The results suggest that irrigation at 0.2 CWSI could be a promising option for achieving higher kernel and stover yields with minimal water use and maximum WUE and IUE.
RESUMO
Remote sensing has played a vital role in advancement of agriculture and is effective technical method for agriculture crop management. It is a technology which acquisite information regarding objects on earth surface as well as atmosphere from a distance without being in contact with the object. Researchers have proved its high potential with accuracy in the field of agriculture. After various experiments, the qualitative and quantitative assessment of soil, crop and atmosphere demonstrated the better understanding between the crop and its management practices. The collected spatial and temporal data via various passive and active sensors has been utilized not only for morphological study but also for monitoring the vegetation moisture content. The paper reviews about the potential studies carried out to investigate the water content in plant to make use in irrigation management. Diverse spectral reflectance indices have been mentioned from which special emphasis on NDWI has been given. It is an index which is used in remote sensing to assess the crop water status and can be utilized in efficient operation of irrigation to improve water use efficiency (WUE) in agriculture. In order to make irrigation practices more efficient by making the lab restricted irrigation scheduling methods like IW:CPE method applicable in regular practice by using remote sensing. This paper firstly identifies areas where researches and techniques have real-world application. Next, it identifies actual issues that remote sensing could address and solve with further research and its related development. All opportunities for managing agricultural water resources effectively to be explored and made successful through precision agriculture. Using the fast, impartial and reliable information offered by remote sensing is a significant difficulty in the field of water resource management.