Effects of tropical legume cover crops on soil quality at dryland farming area in Bali, Indonesia

Two field experiments were conducted to study the effects of tropical legume cover crops on soil quality in dryland farming areas at Angantaka village, Badung regency, Bali Province of Indonesia from June to November 2013. In the first experiment, three tropical legume cover crops (LCC) (Centrosema pubescens L.(Cp), Mucuna pruriens L.(Mp) and Pueraria javanica L. (Pj)) and one control (without LCC) were arranged in a randomized complete block design with four replicates.

Variables measured were the quality of LCC biomass, C-absorbed and fixed-N by LCC. The LCCs were harvested after three months, which were then incorporated into the soil according to the treatments set for the second experiment. Design for the second experiment was a Split-plot with four replicates, where residues (biomass) of three LCC (results of the first experiment) were assigned as the main plot and four times of biomas incorporation (0,10, 20 and 30 days) as the subplot. Results showed that Pj was the best LCC crop among others (Cp and Mp) due to its highest quality. Pj also had the highest absorbed-carbon (58.50 t ha-1), fixed-N (490.21 kg ha-1), biomass FW and DW (304.83 and 116.99 t ha-1) among LCC species.

The treatment of Pj with 30 days biomass incorporation significantly improved the soil quality as indicated by the highest soil moisture content (40.25%) and porosity (79.90%), organic-C (1.95%), total N (0.09%), available-P (15.71 mg kg-1), exchangeable-K (2.07 mg kg-1) and soil respiration (63.94 meC-CO2 kg-1day-1).

• This Article is Authored by Gusti Ayu Mas Sri Agung*, Ketut Sardiana, Gusti Made Oka Nurjaya

Udayana University, Bukit Jimbaran-Badung, Bali, Indonesia

FULL ARTICLE AVAILABLE AT: Volume 6, Number 3, March 2015 – IJAAR (P.12-19)
PUBLISHED JOURNAL NAME:  International Journal of Agronomy and Agricultural Research (IJAAR)

Read More

Carbon sequestration and soil quality under organic system of local rice (Oryza sativaL.) variety in Tabanan, Bali Indonesia

I. Wayan Diara, I. Made Adnyana, I.B. Putra Manuaba, I.G.A. Mas Sri Agung* 

• Udayana University, Bukit Jimbaran-Badung, Bali, Indonesia

Soil organic carbon (SOC) storage has been widely considered as a measure for mitigating global climate change through C sequestration (SOCS) in soils. A study was conducted by evaluating  SOC, total N, available P, K, bulk density, and total soil microbes under organic system and conventional of Local rice variety at the same time in two farmer fields (subak Jatiluwih and Wangaya Betan at Mangesta village in Penebel district,Tabanan regency, Bali Indonesia. Half of farmers in those two locations have been managing certified organic system with Red local rice variety for two years (2010-2012), while the other half maintaining conventional system. Composite soil samples were taken at three points at depth of 0-20 cm and 20-40 cm in three replications at each location. Results showed that after two years, organic system resulted in better soil quality and higher SOCS only in Jatiluwih. Significantly higher SOC (3.338%), total N (0.252%), available P (15.84 ppm), K (133.63 ppm), bulk density (0.510 Mg m-3) and higher SOCS (81.354 Mg ha-1) were recorded under organic compared to conventional system. In Wangaya Betan, those components, except bulk density, were not different under two systems. The yield of Red local rice variety under organic was 6.44.t ha-1 compared to 5.12 t ha-1 under conventional system.

Reference: Volume 5, Number 3, September 2014 – IJAAR

---

Read More