DOI : http://dx.doi.org/10.21776/ub.jpt.2023.008.2.01
Growth Yield and Nutrient Requirement of Adlay (Coix lacryma-jobi L.) Applied with Different Levels of Nitrogen in Bukidnon Philippines
Michelle Mae Recla Miñoza* 1, Juvelyn Yacunas Planas1, John Rey Natinga Labajo* 3
1Department of Soil Science, College of Agriculture, Central Mindanao University, University Town, Musuan, Maramag, Bukidnon, Philippines 8710
Department of Agriculture, College of Agriculture, Agribusiness, Forestry, and Food Science, Cotabato Foundation College of Science and Technology
[email protected], [email protected] submitted 30 June 2023 / accepted 25 August 2023
ABSTRACT
The study was conducted at Agricultural Experiment Center, Central Mindanao University, Musuan, Maramag, Bukidnon from August 2018 to January 2019 with the following objectives: (1) evaluate the effects of different rates of N on the soil chemical properties at harvest; (2) evaluate the effects of different rates of N on the growth of adlay; and (3) determine the cost and return analysis of adlay applied with different rates of Nitrogen. The field experiment was laid out in Randomized Completely Block Design (RCBD) with six treatments, replicated thrice with 18 experimental units. The fertilizer rate used for the experimental site was 50 kg of P2O5 ha-1 and 20 kg of K2O ha-1. Different Nitrogen rates were used (0, 30, 60, 80, 100, 120 kg ha-1). Based on the results, soil properties, including pH and extractable P at harvest, were noted to be not significantly affected by the application of different treatments; however, organic matter and exchangeable K were significantly affected by the treatments. Treatment 4, with 80 kg N ha-1,has the highest grain yield and return on investment, hence the most economical treatment.
Keywords: Adlay (Coix lacryma-jobi L.), Grain yield, Nutrient requirement, Rates of Nitrogen
INTRODUCTION
Adlay (Coix lacryma-jobi L.) is a member of the grass family Poaceae and a grain-producing perennial plant native to Southeast Asia. Adlay can be primarily consumed as a staple crop substitute for rice and corn. Aside from being a staple crop, adlay can be processed into flour for bread, wine, and beer production. The grain can also be roasted before husking and used in cakes, soups, porridge, and other foods. Adlay is primarily developed in Zamboanga del Sur, Isabela, Batangas, Romblon, and Bicol Region. The crop is also referred against
inflammatory, antihistaminic, muscle relaxant, fever-reducing, and sugar-lowering properties. A decoction of the roots is used as a vermifuge and to treat dysentery, gonorrhea, and menstrual disorders (Jansen, 2006).
The extracts of adlay found that it significantly inhibited fatty acid synthase activity in the liver. This is vital because human cancer cells contain high levels of fatty acid synthase, a substance linked to aggressive tumor cell growth (Van de Venter et al., 2008). Adlay is often given as fodder, especially for cattle and horses. Adlay is also
considered one of the most nutritious, healthy foods in Asian countries such as China, India, Pakistan, Sri Lanka, and Malaysia. Nitrogen is essential for achieving grain yield, quality targets and results in maximum economic return. It is an essential component of chlorophyll, enzymes, proteins, etc. Aside from that, it stimulates root growth and crop development, and the uptake of other nutrients. Good nitrogen management also makes good environmental sense.
Application of nitrogen fertilizer results in higher biomass yield, protein yield, and concentration in plant tissue which is commonly increased. The nitrogen supply for adlay comes from fertilizer, as well as from manures. In cereals, an abundant supply of Nitrogen declines the relative proportion of lysine and threonine. Along these lines, it can lessen the quality of protein. The level of crop growth determines the amount of Nitrogen required by the crop- the greater the development, the higher the crop requirement` for Nitrogen.
Thus, the study aimed to assess the growth, yield, and nutrient requirement of adlay applied with different Nitrogen levels.
This specifically aimed to (1) evaluate the effects of different rates of N on the soil chemical properties at harvest; (2) evaluate the effects of different rates of N on the growth and yield of adlay; and (3) determine the cost and return analysis of adlay applied with different rates of Nitrogen.
MATERIALS AND METHODS Experimental Design and Treatments
he experiment was carried out in a Randomized Completely Block Design (RCBD) with six (6) treatments and replicated three (3) times. The area (493 sq. meters) was divided into three blocks, and each block was further subdivided into six plots with a dimension of 4m x 5m.
Time and Place of the Study
The field study was conducted at the Agricultural Experiment Center (AEC), Musuan, Bukidnon. The soil chemical properties were performed at the Soil and Plant Analysis Laboratory (SPAL), Department of Soil Science, College of Agriculture, from August 2018 to January 2019.
Seed Preparation and Planting
The seeds were soaked in water for eight (8) hours and incubated for six (6) hours before sowing. Pre-germinated seeds were sown 60 cm apart in the row with five (5) seeds per hill and then covered with soil.
(Aradilla, 2016).
Treatment Application
The soil analysis results from the Soil and Plant Analysis Laboratory were used as a basis for the fertilizer application of different treatments. Adlay does not have a fertilizer recommendation yet, and corn was used as a basis for supplying the P and K needs of the crop since they belong to the same family.
The fertilizer rate used for the experimental site was 50 kg of P2O5 ha-1 and 20 kg of K2O ha-1. A blanket application of 277.77 kg ha-1 of Ordinary super phosphate (0 – 18 – 0) was applied in every treatment, and 33.33 kg ha-1 of muriate of potash (0 – 0 – 60). P was applied 45 days after sowing, and K 12 was applied on the 45th and 60th days of the plant.
The amount of Nitrogen (N) was applied during planting and 45 days after planting based on the different Nitrogen rates.
Cultivation and Maintenance
Rows were cultivated three to four weeks after sowing to remove the weeds (off- barring). Thinning was done two weeks after planting, maintaining four healthy plants per hill. Hilling up was done 45 days after planting to control the weeds. No chemical control of weeds and insect pests was employed in the experimental trial.
Table 1. Treatments and their description
TREATME
NT DESCRIPTION
T1 0-50-20 kg of N - P2O5 - K2O ha-1 T2 30-50-20 kg of N - P2O5 - K2O ha-1 T3 60-50-20 kg of N - P2O5 - K2O ha-1 T4 80-50-20 kg of N - P2O5 - K2O ha-1 T5 100-50-20 kg of N - P2O5 - K2O ha-1 T6 120-50-25 kg of N - P2O5 - K2O ha-1 Methods used in the soil chemical properties
Soil chemical properties used in the study are the following: Potentiometric Method (1:5 soil-water ratio) (Biddle, 1997),
% organic matter determination, Walkley and Black method, and Bray P2 (0.1 N HCl+0.03 N NH4F) method for exchangeable Phosphorus using UV-Vis spectrophotometer and exchangeable potassium 1N NH4OAc, pH seven extraction using flame photometer (PCARRD, 1991).
Harvesting
Harvesting was done manually. A sickle was used to cut the stem and branches of the plant. Branches were separated with adlay grains for threshing through hand picking.
Harvested panicles were cleaned and sundried for two to three days until 10-14%
MC was reached.
Soil Sampling and Analysis
Soil analysis was done at the Soil and Plant Analysis Laboratory (SPAL), Department of Soil Science, College of Agriculture, CMU, Musuan, Bukidnon. The initial analysis results were the prime basis for the fertilizer recommendation.
Statistical Analysis
Data were statistically analyzed using the Analysis of Variance (ANOVA) in Randomized Completely Block Design.
Differences between treatment means were compared using the Honestly Significant Difference (HSD) Test.
Return on Investment
Return on investment (ROI) was estimated based on the prevailing cost of inputs and the selling price of adlay seeds
when sold in the market. The production cost per hectare was deducted from the gross sales to obtain the net return. The return on investment (ROI) was computed using this formula: ROI= Net income divided by the cost of production x100 Where: Net income = Gross income – Total Cost of Production.
RESULTS AND DISCUSSIONS Initial Soil Properties
Table 2 shows the initial chemical properties of the soil before sowing. Based on the results, the soil has a pH of 6.02, considered moderately acidic based on qualities described by Hoskins (1997). The soil organic matter content is 2.34%, regarded as marginal (PCARRD, 1991).
Moreover, the extractable P content is 10.70 mg kg-1, which is low (Landon, 1984). The exchangeable K content with the value of 0.18 cmol kg-1 is considered low, according to Landon (1984).
Table 2. Initial chemical properties of soil in the experimental area
PROPERTIES VALUE DESCRIPTION
pH 6.02 Moderately Acidic
OMC, % 2.34 Marginal
Extr. P, mg kg-1 10.70 Low Exc. K, cmol kg-1 0.18 Low
Soil Chemical Properties at Harvest Soil pH
Table 3 shows the average soil pH values at harvest and no significant difference between treatment means. The average soil pH values in the study ranged from 5.31 – 6.05. Among treatments, Treatment 5 had the highest pH value of 5.57, followed by Treatment 2 (5.64), Treatment 6 (5.62), Treatment 1 (5.57), and Treatment 4 (5.42), while Treatment 3 had the lowest pH with a value of 5.31.
Table 3. Properties of the soil at Harvest
TREATMENT SOIL CHEMICAL PROPERTIES
CODE DESCRIPTION pH OM†
(%)
Ext P, (mg kg-1)
Exch K, (cmol kg-1)
T1 0-50-20 kg of N ha-1 5.57 1.30 b 4.87 0.33 b
T2 30-50-20 kg of N ha-1 5.64 2.91 ab 4.83 0.27 b
T3 60-50-20 kg of N ha-1 5.31 3.30 a 4.26 0.31 b
T4 80-50-20 kg of N ha-1 5.42 3.83 a 5.06 0.31 b
T5 100-50-20 kg of N ha-1 6.05 2.80 ab 5.27 0.47 a
T6 120-50-25 kg of N ha-1 5.62 3.10 ab 5.26 0.59 a
F test ns * ns **
CV, % 7.20 23.83 22.30 13.81
Note: Means followed by the same letters are not significantly different at a 5% level of significance based on HSD Blanket application of 50 kg P2O5 ha-1, and 20 kg K2O ha-1, ns – not significant * – significant, ** – highly significant
Soil Organic Matter Content
The organic matter content at harvest is shown in Table 4. The average organic matter content of the soil had values ranging from 1.3 – 3.83%, with Treatment 1 (1.30%) having the lowest value and showing a significant difference between Treatment 3 (3.30%) and Treatment 4 (3.83%). No significant difference was observed between Treatment 2 (2.91%), Treatment 5 (2.80%), and Treatment 6 (3.10%). Treatment 4 (3.83%) had the highest value and showed a significant difference between Treatment 1 (1.30%), but no significant difference was noted between Treatment 2 (2.91%), Treatment 3 (3.30%), Treatment 5 (2.80%) and Treatment 6 (3.10%). Based on the results, it was found that treatments applied with Nitrogen had greater soil organic matter content at harvest compared to the treatment with no application of Nitrogen (control).
Kibblewhite et al. (2008) mentioned that using nitrogen fertilizer for crop production influences soil health primarily through changes in organic matter content, microbial life, and soil acidity. A study by Bullock (2005) proves that temperature and rainfall influence the amount of organic matter found in soils.
The organic matter content tends to increase if the climate moves from warmer to cooler weather. According to Paul et al. (1997), for
every decline in temperature, the organic matter increases by two to three times. Also, organic matter is higher in grassland soil than in forests. Grasses were used as mulching material during weeding, enriching the soil's organic matter. Nitrogen fertilizer, when applied as per the need of the field crops in a balanced proportion, maintains or improves yield and soil health rather than deleterious (Liu et al., 2006).
Soil Extractable Phosphorus
Extractable phosphorus content at harvest is shown in Table 3 and was not significantly affected by the treatments. The extractable phosphorus content of the soil varied from 4.26 – 5.27 mg kg-1. The application of Treatment 5 had the highest phosphorus content of 5.27 mg kg-1, followed by Treatment 6 (5.26 mg kg-1), Treatment 4 (5.06 mg kg-1), Treatment 1 (4.87 mg kg-1), and Treatment 2 (4.83 mg kg-1) while Treatment 3 had the lowest phosphorus content of 4.26 mg kg-1.
Soil Exchangeable Potassium
Table 3 shows the exchangeable potassium content of the soil at harvest, wherein values range from 0.27 – 0.59 cmol kg-1. Treatment 6 had the highest value of 0.59 cmol kg-1 and showed significant difference between Treatment 1 (0.33 cmol kg-1), Treatment 2 (0.27 cmol kg-1), Treatment
3 (0.31 cmol kg-1) and Treatment 4 (0.31 cmol kg-1) but shows no significant difference between Treatment 5 (0.47 cmol kg-1).
Treatment 3 had the lowest value of 0.27 cmol kg-1 and shows significant difference between Treatment 5 (0.47 cmol kg-1) and Treatment 6 (0.59 cmol kg-1) and no significant difference between Treatment 1 (0.33 cmol kg-1), Treatment 2 (0.27 cmol kg-1) and Treatment 4. (0.31 cmol kg-1). Castillo and Bacayan (2016) mentioned that mulching of sunflower leaves increased the potassium content of the soil at harvest due to its decomposition.
Yield and Yield Components of Adlay Number of Productive Tillers
The treatments do not significantly affect the number of productive tillers (Table
4). The number of tillers ranged from 4.37 to 7.33. Treatment 4 had the highest value, with 7.33, while Treatment 2 had the lowest number, with 4.67. During the planting season, the months of August and September experienced drought due to climate change, which significantly affected the productivity of adlay. This study confirmed the result of Sacarum and Aradilla (2012) that tillers of adlay during drought were lesser than when grown under normal field conditions. Prasad et al. (2008) mentioned that drought and heat stress affects the whole plant process from germination, growth and development, floral initiation, pollination, fertilization, seed development, yield, and quality.
Table 4. Properties of the soil at Harvest
TREATMENT PARAMETER
CODE DESCRIPTION NUMBER OF
PRODUCTIVE TILLERS
GRAIN YIELD (kg ha-1)
T1 0-50-20 kg of N ha-1 5.67 1067.57 d
T2 30-50-20 kg of N ha-1 4.67 1203.50 c
T3 60-50-20 kg of N ha-1 6.67 1433.33 b
T4 80-50-20 kg of N ha-1 6.67 1677.47 a
T5 100-50-20 kg of N ha-1 7.33 1515.27 b
T6 120-50-25 kg of N ha-1 6.00 1116.33 cd
F test NS **
CV, % 17.01 4.50
Note: Means followed by the same letters are not significantly different at a 5% level of significance based on HSD Blanket application of 50 kg P2O5 ha-1 and 20 kg K2O ha-1 ns – not significant ** – highly significant
Grain Yield
Grain Yield is shown in Table 5 and was found to have a highly significant effect by the treatments. Treatment 4 had the highest yield of 1,677.47 kg ha-1, followed by Treatment 5 with a yield of 1,515.27 kg ha-1, Treatment 3 with an output of 1,433.33 kg ha-1, Treatment 2 with a yield of 1,203.50 kg ha-1, Treatment 6 with a yield of 1,116.33 kg ha-1, and the lowest from Treatment 1 with a yield of 523.26 kg ha-1. The yield of different treatments was also affected by climate and environmental
factors. Adlay planted and grown in months with limited rainfall had lower results. Further, grains of other treatments were attacked by rice birds during off-seasons indicating that rice birds considered adlay as alternate food, particularly the Gulian variety.
Moreover, during dry months (August to September), adlay plants were severely affected due to less or no available soil moisture. According to Tollenaar et al. (1978), even a minor drought during the physiologic stages of the 21 crops can reduce the yield
significantly. Likewise, Chandrasekharan et al. (2010) mentioned that weather plays a decisive role in crop production, contributing to 50% variations. Despite the drought condition, it also gave potential yield.
According to BAR (2011), the average yield of adlay, specifically the gulian variety, ranges from 1,500 kg ha-1 to 2,500 kg ha-1 under favorable conditions. Moreover, applying inorganic fertilizers was contradictory to the results of Coles (2013); the Gulian variety was the highest yield when applied with organic fertilizers.
Return on Investment
A cost and return analysis were done to determine the different treatments'
profitability. Table 5 shows the return on investment of adlay production. The highest return on investment was obtained from Treatment 4 with an ROI of 201.93%, which was significantly different from Treatment 1 with a value of 87.60%, Treatment 2 with a value of 137.18%, Treatment 3 with a value of 167.53%, Treatment 5 with a value of 170.55% and Treatment 6 with a value of 111.06%. The lowest ROI was obtained from Treatment 1 with a value of 87.60%, which has no significant difference from Treatment 6 (111.06%) but significantly different from Treatment 2 (137.18%), Treatment 3 (167.53%), Treatment 4 (201.93%) and Treatment 5 (170.55%).
Table 8. Return on investment of adlay applied with different levels of Phosphorus TREATMENT
ROI, %
CODE DESCRIPTION
T1 0 kg of N ha-1 87.60 d
T2 30 kg of N ha-1 137.18 bc
T3 60 kg of N ha-1 167.53 b
T4 80 kg of N ha-1 201.93 a
T5 100 kg of N ha-1 170.55 ab
T6 120 kg of N ha-1 111.06 cd
F test **
CV, % 15.22
Note: Means followed by the same letters are not significantly different at a 5% level of significance based on HSD Blanket application of 50 kg P2O5 ha-1 and 20 kg K2O ha-1, ** – highly significant
CONCLUSION
Results obtained were used to conclude that the application of inorganic fertilizer was still an efficient source of nutrients to supply the crop's needs. This will be justified by the different treatments containing different Nitrogen levels.
Treatments applied with nitrogen fertilizer had greater soil organic matter content at harvest compared to the treatment with no application of Nitrogen (control). Moreover, applying nitrogen fertilizer did not significantly affect the soil pH, extractable P, and the number of productive tillers. Adlay plants that used Treatment 4 appeared to be the highest grain yield. Also, Treatment 4 was observed to be
the highest return. The treatment combination of 80 – 50 –20 kg of N – P2O5 – K2O ha-1 gave the best performance, in which Treatment 4 performed better than Treatment 1 (control). Therefore, inorganic fertilizers can be recommended according to the agroecological diversity of agricultural areas, with support systems of integrated nutrient management, particularly in areas of low soil fertility. However, it is also recommended that further studies be conducted in the same conditions but in different locations being considered in this study to evaluate the yield of adlay applied with varying levels of Nitrogen on a long-term basis. Thus, sound
and reliable recommendations may be given if this recommendation is considered.
ACKNOWLEDGEMENT
With boundless love and appreciation, the author would like to extend her heartfelt gratitude and appreciation to the many who helped her bring this study into reality. First and foremost, the author would like to offer this endeavor to the Almighty God for giving her strength, peace of mind, and good health to finish the study.
The author would like to express her sincere gratitude to her adviser Juvelyn Y.
Planas for the continuous study support and her patience, motivation, immense knowledge, guidance, and advice during the study. Appreciation is also extended to the panel members, Dr. Myrna G. Pabiona and Dr. Nonilona P. Daquiado, for their insightful comments, encouragement, and improving the things about the author’s study.
To the Soil Science Department faculty members for their help, support, and imparting their knowledge to the author to finish the study. To SPAL staff who contributed a lot to the laboratory analysis. To her parents, Mrs. Roena Miñoza and Mr.
Elmer Miñoza, Gabrielle, and John Elmer, who has provided her with moral and emotional support in life. Also, for their love, prayer, and sacrifices for educating and prospering the author for her future. To Landbank-IRRI Gawad Patnubay Scholarship Program for helping the author’s needs in funding the study. Finally, many thanks and appreciation to every significant person who was missed to mention by the author.
REFERENCES
Alamag, C.A. 2012. Adaptability Trial of Three Adlay (Coix lacryma-jobi L.) Varieties under Musuan Condition. Unpublished Undergraduate Thesis, Central Mindanao University, University Town, Musuan Bukidnon.
Aradilla, A.R. 2016. Phased planting:
determining the best time to plant adlay (Coix lacryma-jobi L.) in Southern
Bukidnon, Philippines. International Journal of Education and Research.
Vol. 4 No. 5
Aradilla, A.R., Detalla M.E.B. & Vallador D.M.
2012. CMU-DA-BAR Adlay R and D Project Annual Report: Development and Promotion of Adlai (Coix lacryma- jobi L.) As Alternative Staple Food, Central Mindanao University, University Town, Musuan, Bukidnon.
Bangod, A.V.A. 2012. Hill Distances and Plants per Hill: Effects on Agronomic and Yield Performance of Adlay.
Unpublished Undergraduate Thesis, Central Mindanao University, University Town, Musuan, Bukidnon.
BAR Conducts Tests on Adlai, Alternative to Rice and Corn 2011. Retrieved April 07,
2018, from
http://www.bworldonline.content.php?
Biddle, D.L. 1997. A Compilation of Selected Methods for Soil and Plant Analysis.
Department of Agriculture, the University of Queensland, Australia.
Bullock, P. 2005. Encyclopedia of Soils in the Environment. Cranfield University- Silsoe, Silsoe, UK.
Chandrasekharan M.B., Huang F., Chen Y.C.
& Sun Z.W. 2010. Histone H2B C- terminal helix mediates trans-histone H3K4 methylation independent of h2b ubiquitination. Mol. Cell. Biol.
30(13):3216-32.
Chatterton, K. (Artist). The nitrogen cycle schematic presentation. Retrieved from http://wedc-knowledge.lboro.ac.uk.
Cheng H.C., Huang Y.C. & Hung W.C. 2003.
Ant Proliferative and Chemo Preventive Effects on Adlay Seed on Lung Cancer in Vitro and in Vivo. J Agric Food Chem.
Cheng P., Mackerras A. & Ching Y.H. 2001.
Hanyu for Beginning Students. Taipei, Taiwan.
Castillo H.B. & Bacayan J.J. 2016. Evaluation of Mulching Materials in Selected Highland Vegtables. BPI-BNCRDPSC, Guisad, Baguio City. 26
Coles, M.F.T. 2013. Organic Fertilizer Effects on the Performance of Three Adlay (Coix lacryma- jobi L.) Varieties.
Undergraduate Thesis, Central
Mindanao University, Musuan, Bukidnon.
De Smedt, J.M. 1991. Collaborative study of the International Office of Cocoa, Chocolate and Sugar Confectionary on Salmonella detection from cocoa and chocolate processing environmental samples. Int. J. Food Mocrobial.
Department of Science and Technology 2016. GOVPH. Retrieved April 07,
2018, from
http://dost.gov.ph/knowledge-
resources/news/45- 2016-news/978- dost-steps-up-adlai-crops-with-
irradiation-technology.
Food and Nutrition Research Institute (FNRI) Chemical Analysis 2011. Nutritional Facts of Adlai Grits.
Hoskins, B.R. 1997. Soil Testing Handbook for Professionals in Agriculture, Horticulture, Nutrient and Residuals Management, 3rd ed. Maine Forestry and Agricultural Experiment Station, University of Maine, Orono, Maine, USA.
Jansen, F.C.M. 2006. Coix lacryma-jobi L.
Retrieved from
http://www.database.prota.org/
KIbblewhite, M.G., Ritz K. & Swift M.J. 2008.
Soil health in agricultural systems.
Philos. Trans. R. Soc. 363, 685-701.
Killpack, S. & Buchholz, D. (n.d.). Nitrogen in the Environment Nitrogen Cycle.
Retrieved April 07, 2018 from http://extension2.missouri.edu/.
Kimata, M. & Nakagome, T. 1982.
Comparative Studies on Growth Habit and Growth Pattern of Coix lacryma-jobi L. var. ma-yuen and var. lacrymajobi, Gramineae, Tokoyo Gakugei University, Kagonei, Japan.
Kogel J.E. 2006. Industrial Minerals and Rocks: Commodities, Markets and Uses. SME (ed.). p. 964. ISBN 0873352335.
Landon, J.R. 1984. Booker Tropical Soil Manual. Booker Agriculture International Limited, London.
Llemit, G.M.H 2013. Field Performance of Job’s Tears at Different Planting Distances. Unpublished Undergraduate
Thesis, Central Mindanao University, University Town, Musuan, Bukidnon.
Liu, X., Herbert S.J., Hashemi A.M., Zang X.,
& Ding G. 2006. Effects of agricultural management on soil organic matter and carbon transformation – A review. Plant Soil Environ. 52, 531-543. 27
Mahbod, M., Sepaskha A.R. & Sepaskha S.
2014. Estimation of yield and dry matter winter wheat using logistic model under different irrigation water regimes and nitrogen application rates. Archives of Agronomy and Soil Science 60: 1661- 1676.
Mosier, A.R., Syers J. & Freney J.R. 2004.
Nitrogen fertilizer: An essential component of increased food, feed and fiber production. In Agriculture and the Nitrogen Cycle: Assessing the Impacts of Fertilizer of Use on Food Production and the Environment, pp. 3-15. SCOPE 65, Paris France.
Paul, E.A., Paustian K., Elliot E.T. & Cole C.V.
1997. Soil Organic Matter in Temperate Agroecosytems: Long-Term Experiments in North America. Boca Raton, FL,: CRC Press.
PCARRD. 1991. Standard Method of Analysis for Soil, Plant Tissue, Water and Fertilizer. PCAARD, Los Baños, Laguna.
PCSO. 1983. Samaka Guide to Homesite Farming. Philippine Charity Sweepstakes Manila.
PhilRice. Rice-Adlai, New Blend for the Palate. 2016. Retrieved April 07, 2018, from http://www.philrice.gov.ph.
Prasad, P.V.V., Staggenborg S.A., Ristic A.
2008. Impacts of Drought and/or Heat Stress on Physiological, Developmental, Growth and Yield Processes of Crop Plants. pp. 305-355.
IN:
www.personal.kstate.edu/prasad.pvv- aasm-Chapter11.pdf.
Schmid T. M., Varma A., Drgon T., Browers B. & Cabib E. 2003. Septins under clap regulation and chitin ring are required for neck integrity in budding yeast. Mol Bio Cell 14(5):2128-41.
Sarucam, I.V. & Aradilla A.R. 2012. Field Performance of Job’s Tears at Different
Planting Distances. Unpublished Undergraduate Thesis. Central Mindanao University, University Town, Musuan, Bukidnon.
Sommers, M.A. 2007. Phosphorus. The Rosen Publishing Group. p. 25. ISBN 1404219609.
Strous, M. & Jetten M.S.M. 2004. Anaerobic oxidation of methane and ammonium.
Annu. Rev. Microbial. 58, 99-117.
Tollenaar, M. & Daynard T.B. 1978. Dry weight, soluble sugar content and starch content of maize kernels during early post silking period. Can. J. Plant Sci. Ann-33, 729-736. 28
Tumapon, A., Doctolero K.J.T., Lapoot C.R. &
Salvani J.R. 2012. Development and Promotion of Adlai (Coix lacryma-jobi L.) as an alternative staple food in Northern Mindanao [Philippines].
AGRIS: International Information System for the Agricultural Science and Technology. Retrieved April 07, 2018 from http://agris.fao.org/.
Van De Venter M., Roux S., Bungu L.C., Louw J., Crouch N.R., Grace O.M., Maharaj V., Pillay P., Sewnarian P., Bhagwandin N. & Folb P. 2008.
Antidiabetic screening and scoring of 11 plants traditionally used in South Africa.
Department of Biochemistry and Microbiology, Nelson Mandela Metropolitan University, South Africa.
Yoshida, H., & Horie T. 2010. A model for stimulating plant N accumulation, growth and yield of diverse rice genotypes grown under different soil and climatic condition. Field Crop Research 117: 122-130.