Nitrogen Uptake and Nitrogen Demand of Potatoes on Sandy Soil PDF Download

Author: Ashmita Rawal
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ISBN:
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Languages : en
Pages : 0

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Book Description
The study focused on optimizing potato production and nitrogen (N) management practices on sandy soils. The research covered several key areas, including the effect of N rates on yield and nitrogen use efficiency (AE), variations in dry matter and N uptake patterns among potato varieties, the use of visible-near infrared (vis-NIR) spectroscopy to estimate leaf N status, and the influence of soil organic matter (SOM) on potato productivity in sandy soils. The study began with a systematic review and meta-analysis, which examined the relationship between N rates and yield, as well as N rates and agronomic N use efficiency. The analysis showed that N fertilization had a significant effect on yield, with an optimal N rate of 236 kg N ha-1. Additionally, it revealed a linear decrease in agronomic N use efficiency as N fertilization increased. Furthermore, investigating potato varieties, the research found variations in dry matter and N uptake patterns in both vines and tubers. Different potato varieties responded differently to N fertilization, affecting vine response patterns. However, variations in tuber biomass were primarily attributed to the specific potato varieties rather than N fertilizer rates. The thesis also validated the use of vis-NIR spectroscopy as a cost-effective and efficient method for monitoring leaf N status in potatoes. A model using partial least square regression (PLSR) was developed, demonstrating high predictive performance in estimating total N content in leaves. However, the accuracy of the model was decreased when total N contents exceeded 6 %. Finally, the study examined the impact of SOM levels on potato productivity in sandy soils. Soil samples from various fields were collected, and a greenhouse study was conducted. The results indicated that SOM positively influenced plant productivity, with significant effects observed in multiple productivity metrics. It was also found that N mineralization acted as a partial mediator of the SOM effect on productivity, demonstrating that SOM enhances plant productivity through mechanisms beyond simple N acquisition. In summary, the thesis provides valuable insights for potato production in the Midwestern agroecological region. The findings emphasize the importance of variety-specific responses to N fertilization, validate vis-NIR spectroscopy as a tool for monitoring leaf N status, and highlight the importance of SOM on potato productivity in sandy soils. These findings can help farmers and researchers optimize potato production, reduce N losses, promote sustainability, and maximize resource utilization in agriculture.