Skip to main content

Response of Improved Rainfed Rice Varieties to Low Soil Nitrogen | Chapter 12 | New Perspectives in International Plant and Soil Research Vol. 1

Nitrogen is one of the major essential plant nutrients and a key input required for better crop yields and therefore scarcity of nitrogen fertilizer has been a major constraint to rice production particularly in developing countries. Low soil fertility prevalent in farmer’s fields has led to low rice yields and the ever escalating fertilizer prices have made this important input unaffordable to most smallholder farmers who have limited resources for purchasing the required inputs. There has been concerted efforts to identify rice varieties that are tolerant to low soil nitrogen since varieties differ in their ability to impact productivity and some varieties can perform well under low nitrogen input.The Mwea Upland rice (MWUR) varieties have been bred under low fertilizer input environment while other authors have indicated that the New Rice for Africa (NERICA) gives high yields under low input conditions. There is therefore need to identify the superior rice varieties that are adaptable to low soil nitrogen levels. Thus, the objective of this study was to investigate the effects of different rates of nitrogen fertilizer on improved upland rice varieties and to identify the low input adaptable varieties. Field studies were conducted at Alupe in Western Kenya under rainfed upland conditions between August 2012 and April 2013. The experimental layout was split plot factorial in a Randomized Complete Block Design with three replicates. The main plot treatments were four rates of nitrogen fertilizer levels which were; 0 (control), 40, 80 and 120 kg ha-1 applied as calcium ammonium nitrate (26% N) in two equal splits; 21 days after sowing (DAS) and at panicle initiation (46 DAS). Sub-plots consisted of four MWUR varieties namely MWUR 1, MWUR 2, MWUR 3, MWUR 4; and four NERICA varieties namely NERICA 1, NERICA 4, NERICA 10 and NERICA 11. The parameters measured included plant height, tiller number, filled grain ratio percentage and yield components. In the study, nitrogen treatment showed significant effect on plant growth and the measured parameters increased significantly with increase in nitrogen level. MWUR varieties studied were more adaptable to low nitrogen conditions as compared to NERICA varieties. The NERICA varieties recorded higher yield at high nitrogen levels as compared to MWUR varieties. However, NERICA 4 gave higher yield as compared to other NERICA varieties regardless of the nitrogen level. Results from our study suggest that MWUR 1 and 2 and NERICA 4 were more tolerant to low nitrogen as compared to MWUR 3 and 4 and NERICA 1, 10 and 11, because of higher height, more tiller number, higher filled grain ratio percentage and higher yield component as compared to the other studied varieties and may be suitable for soils low in nitrogen.


Author(s) Details

Dr. P. A. Sikuku
Department of Botany, Maseno University, P.O.Box 333 Maseno, Kenya.

Dr. J. M. Kimani
Kenya Agricultural Research Institute-Mwea-Tebere, P.O.Box 298-10300, Kerugoya, Kenya.

Dr. J. W. Kamau
EAAPP PCU, P.O.Box 30028 – 00100, Nairobi, Kenya.

S. Njinju
Kenya Agricultural Research Institute-Mwea-Tebere, P.O.Box 298-10300, Kerugoya, Kenya.

View Volume: https://doi.org/10.9734/bpi/npipsr/v1

Comments

Popular posts from this blog

Alkali Element Modification of Glucose Molecules as a Method to Dissolve Cancer Cells | Chapter 12 | New Visions in Medicine and Medical Science Vol. 4

  The present study highlights about alkali element modification of glucose molecules as a method to dissolve cancer cells. The central regulation of the mechanisms governing cell proliferation has little effect on cancer cells. Cancer cells are entirely independent of the central command and divide and proliferate on their own, making it challenging to activate their response mechanism. Precisely, this is the reason why they are at risk to the health of humans and/or any biological entities. Instead of trying to reconnect the central command of the growth control mechanism to cancer cells that are already out of the range, we present a method of using the cancer cell’s own irresponsive and uncontrolled growth mechanism to their disadvantage and destroy the cancer cells. We found that this is achievable in an atomic/molecular level study of the glucose molecule, which is the primary food source used for growth and energy generation by all cells in the body, including the cancer cells.

Risk Factors for Postpartum Psychiatric Disorders. A Review of the Literature | Chapter 8 | New Visions in Medicine and Medical Science Vol. 4

  Objective: The aim of this study was to explore the risk factors for the development of postpartum psychiatric disorders through international literature. Materials and Methods: Throughout many articles in PubMed, Google scholar and PsycInfo, a great amount of recent data was gathered to identify the disorders that are most common as well as their risk factors. Results: After childbirth, most commonly women experience postpartum depression, anxiety disorders, post-traumatic stress disorder and postpartum psychosis. All the disorders have many similar risk-factors with the main one being preexisting psychiatric disorder and many similar symptoms too. Conclusions: Women after childbirth are at risk of experience many psychiatric disorders, such as postpartum distress, postpartum post traumatic stress disorder and even more rarely postpartum psychosis. It is important to provide comprehensive support to ensure the well-being of both the mother and the infant and this will be en

Greening Regional Airports: A Vision for Carbon Neutral Infrastructure | Chapter 12 | Contemporary Perspective on Science, Technology and Research Vol. 3

 This study provides an overview of the energy demand of a regional airport, divided into individual time horizons. The electrification of aircraft systems raises the question of whether airports will be among the largest electricity consumers in our infrastructure in the future. Sustainability and especially emission reductions are significant challenges for airports that are currently being addressed. The Clean Sky 2 project GENESIS addresses the environmental sustainability of hybrid-electric 50-passenger aircraft systems in a life cycle perspective to support the development of a technology roadmap for the transition to sustainable and competitive electric aircraft systems. This article originates from the GENESIS research and describes various options for ground power supply at a regional airport. Potential solutions for airport infrastructure with a short (2030), medium (2040), and long (2050) time horizon are proposed. In addition to the environmental and conservation benefits,