Nitrogen and potassium use efficiency of Bario rice grown on Bekenu series

Sulok, Kevin Muyang Tawie (2007) Nitrogen and potassium use efficiency of Bario rice grown on Bekenu series. [Project Paper] (Submitted)

Text lp FSPM 2007 23.pdf Download (4MB)

Abstract

A pot study was carried with the following objectives: (i) To investigate N and K uptake of Bario rice on Bekenu series (Tipik Tualemk:uts), and (ii) To investigate N and K use efficiency of Bario rice on Bekenu series. Treatments evaluated were: (i) Bario rice under fertilized condition (Tl), and (ii) Bario rice under unfertilized condition (TO). The experiment was conducted in a glasshouse at Universiti Putra Malaysia Bintulu Campus, Sarawak, Malaysia. The type of soil used was Bekenu series. Altogether 18 pots were used having a completely randomized design (CRD) with 9 replications. Nitrogen and K were applied in the forms of urea ( 46 % N) and muriate of potash ( 60 % K2O) at the rates of 0.52 g N and 0.60 g K2O per pot respectively in split application while P was applied in the form of Christmas Island Rock Phosphate (36 % P2Os) at a rate of 0.54 g P2Os per pot (also in split). At 65 days after planting, the Bario rice plants were sampled and partitioned into roots and stem. Their dry weight, N, and K concentrations determined using standard procedures. Soil sampling was done before and after fertilization. Soil total N was determined using the Kjeldahl method while exchangeable K, Ca, Na, and Mg were extracted using the double acid method and their concentrations determined using atomic absorption spectrophotometry. Dry ashing method was used for the determination of K, Ca, Na, and Mg concentrations in plant tissues while the Kjeldahl method was used to determine total N in plant tissues. The concentrations multiplied by the oven dried weight of roots and stem represented N, K, Ca, Na, and Mg uptake in these plant parts. The N and K use efficiencies were then calculated using the subtraction method. With the exception of Ca, urea and KCl (MOP) application significantly increased soil N, K, Mg, and Na concentrations. Total dry weight for both stem and roots showed no significant difference under Tl and TO. Except for Mg concentration in stem and roots, K concentration in stem and that of N in roots were significantly higher under Tl than under TO. The other comparisons showed no significant difference. Due to N and K fertilization, there was significant increase in plant height and number of panicles under Tl compared to TO. Nitrogen, K Na, and Mg uptake in stem were significantly higher for Tl than TO. However, those of roots were not significantly different. The overall N and K use efficiencies of the Bario rice were 9.90 % and 4.23 % respectively, and were considered low, indicating that the rice grown within the time frame of this study did not efficiently utilize these nutrients. This was partly attributed to low N and K recovery during reduced condition and low organic matter status of Bekenu series as Bario rice is noted for being cultivated organically. Additionally, slow adaptation to inorganic fertilization and sudden climatic change involved in this study was_ not ruled out as one of the re.asons for the low efficiency because the rice is traditionally cultivated in the highlands of Sarawak, Malaysia However, with appropriate fertilization and soil maintenance (through research), Bekenu series could be used for Bario rice production. Probably supplementing inorganic fertilizers with organic ones may help to improve growth and development of this rice on Bekenu series. Future studies may consider mimicking or modifying the environment to suit Bario rice growth and development at lower elevations. Certainly, the quality of Bario rice at lower elevations should also be considered in future fertilization programmes or trials.

Item Type:	Project Paper
Faculty:	Faculty of Agriculture and Food Sciences
Depositing User:	Mr. Azman Mohamad
Date Deposited:	17 Dec 2024 02:40
Last Modified:	17 Dec 2024 02:40
URI:	http://psaspb.upm.edu.my/id/eprint/2274

Actions (login required)

View Item