Development, beneficial effects, and economic viability of rice straw and paddy husk composts in combination with clinoptilolite zeolite
Indiscriminate uses of nitrogen (N) fertilizers lead to low N use efficiency and losses through runoff, leaching, denitrification, and volatilization resulting in a series of environmental problems. Clinoptilolite zeolite and composts derived from agricultural wastes could be used to improve N us...
Saved in:
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English |
| Published: |
2016
|
| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/78368/1/FSPM%202016%204%20-%20ir.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Indiscriminate uses of nitrogen (N) fertilizers lead to low N use efficiency and losses
through runoff, leaching, denitrification, and volatilization resulting in a series of
environmental problems. Clinoptilolite zeolite and composts derived from agricultural
wastes could be used to improve N use efficiency by adsorbing NH4
+ ions from urea
and desorbing them timely for Zea mays L. (test crop) use because the clinoptilolite
zeolite, rice straw, and paddy husk composts have high affinity for NH4
+ ions. Thus,
the objectives of this study were to: (i) produce composts through co-composting of
rice straw and paddy husk with chicken slurry amended with clinoptilolite zeolite; (ii)
improve N availability by retaining exchangeable NH4
+ through the use of clinoptilolite
zeolite, rice straw, and paddy husk composts; (iii) determine the use of clinoptilolite
zeolite, rice straw, and paddy husk composts in improving N use efficiency and grain
yield of Zea mays L. cultivation on a tropical acid soil; and (iv) determine the
economic viability of using combination of inorganic fertilizers, clinoptilolite zeolite,
rice straw, and paddy husk composts in Zea mays L. cultivation on a tropical acid soil.
Rice straw compost was produced by mixing 20 kg of rice straw + 1 kg of chicken feed
+ 1 kg of molasses + 1 kg clinoptilolite zeolite + 1 kg urea + 13 L chicken slurry in five
polystyrene boxes and these ratios apply to mixture of paddy husk too. Mature
composts with good agronomic properties, dark brown, soft, coarse with friable texture,
and earthy smell were produced by co-composting rice straw and paddy husk with
chicken slurry and clinoptilolite zeolite as additives. Soil leaching and incubation
studies were conducted for 30 and 90 days, respectively, to determine the effects of
amending urea with clinoptilolite zeolite, rice straw and paddy husk composts on
controlling NH4
+ and NO3
- losses from urea. Urea amended with clinoptilolite zeolite,
rice straw and paddy husk composts significantly controlled NH4
+ and NO3
- release
from urea (soil leaching and incubation studies) compared with urea alone, thus
reducing leaching of NH4
+ and NO3
-. Ammonium and NO3
- leaching losses during the
30 days of leaching and 90 days of incubation were highest in urea alone compared with urea amended with clinoptilolite zeolite, rice straw, and paddy husk composts
treatments. The higher adsorption and lower desorption of NH4
+ in soils with
clinoptilolite zeolite, rice straw, and paddy husk composts corroborated the ability of
clinoptilolite to be used as NH4
+ adsorbent and rice straw and paddy husk composts as
NH4
+ bio-adsorbent. The high buffering capacities of rice straw and paddy husk
composts ensured higher rate of NH4
+ adsorption. Combined use of urea, clinoptilolite
zeolite, rice straw, and paddy husk composts improved soil total N, exchangeable
NH4
+, and available NO3
- compared with urea alone. Soil total hydrolyzable N, NH4-N,
(NH4
+ + amino sugar)-N, amino sugar-N, and amino acid-N soils were higher in soils
with clinoptilolite zeolite, rice straw, and paddy husk composts compared with urea
alone suggesting mineralization of N into available forms of N (NH4
+ and NO3
-) was
affected by the addition of clinoptilolite zeolite, rice straw, and paddy husk composts.
Urea can be amended with clinoptilolite zeolite, rice straw, and paddy husk composts
to regulate availability N for optimum crops use. Promising treatments from the soil
leaching and incubation studies were tested in a pot study using Zea mays L. Thai super
sweet hybrid F1 (test crop) under controlled environment. At 45 days after planting
(tasseling stage of Zea mays L.), amending inorganic fertilizers with clinoptilolite
zeolite, rice straw and paddy husk composts increased soil total N, exchangeable Ca,
Mg, K, and available P. Uptake and use efficiency of P and K of Zea mays L. were
significantly improved upon amending inorganic fertilizers with clinoptilolite zeolite,
rice straw and paddy husk composts. The treatments in the pot study were further tested
in a field trial. A field trial was conducted for 72 days (maturity period of Zea mays L.)
for two consecutive planting cycles of Zea mays L. Amending urea with clinoptilolite
zeolite, rice straw, and paddy husk composts improved N use efficiency because of
temporary adsorption of exchangeable NH4
+ on the negative charge sites of the
clinoptilolite zeolite and organic matter of the rice straw and paddy husk composts. As
a result, N use efficiency and grain yield of Zea mays L. were increased. The use of
inorganic fertilizers, clinoptilolite zeolite, rice straw, and paddy husk composts also
enhanced timely uptake of P, K, Ca, Mg, and Na in the aboveground biomass of Zea
mays L. compared with the conventional use of inorganic fertilizers alone. The higher
retention of N, P, K, Ca, Mg, and Na in the soil regardless of the planting cycle of Zea
mays L. suggests build-up of these nutrients in the soil. This is partly responsible for
the higher fresh cobs yield of the Zea mays L. in the plots with inorganic fertilizers,
clinoptilolite zeolite, rice straw, and paddy husk composts compared with inorganic
fertilizers only. A follow up laboratory study on the field trials was conducted to
determine the effects of clinoptilolite zeolite, rice straw, and paddy husk composts on
decomposition of soil N fractions. Clinoptilolite zeolite, rice straw, and paddy husk
composts increased total hydrolyzable N, NH4-N, (NH4
+ + amino sugar)-N, amino
sugar-N, and amino acid-N compared with urea alone suggesting the clinoptilolite
zeolite, rice straw, and paddy husk composts increased N availability by gradually
hydrolyzing NH4
+ and timely mineralizing NH4
+ for Zea mays L. use. The higher
(NH4
+ + amino sugar)-N, amino sugar-N, and amino acid-N in the soil with
clinoptilolite zeolite, rice straw, and paddy husk composts amendment were
significantly affected by the higher soil total hydrolyzable N and NH4-N following
application of clinoptilolite zeolite, rice straw, and paddy husk composts. Combined
application of inorganic fertilizers, clinoptilolite zeolite, rice straw, and paddy husk
composts did not only improved soil total N availability and N use efficiency but it also
increased P, K, Ca, Mg, and Na availability, uptake, and use efficiency of these
nutrients. Besides, the combination of inorganic fertilizers, clinoptilolite zeolite, rice
straw, and paddy husk increased grain yield of Zea mays L. Economic assessment
study of using clinoptilolite zeolite, rice straw, and paddy husk composts showed higher total costs production of using these amendments in maize cultivation compared
with inorganic fertilizers only. The lower total production costs associated with
conventional practice with lower gross revenue and net revenue are relates to the use of
inorganic fertilizers only. However, higher maize yield, net revenue, and benefit-cost
ratio were obtained for the combined use of inorganic fertilizers, clinoptilolite zeolite,
rice straw, and paddy husk composts in Zea mays L. cultivation and thus, suggest
economic viability of including clinoptilolite zeolite, rice straw, and paddy husk
composts. |
|---|