On the Mechanism of decrease of rice yield in ill-drained paddy field

SUMMARYReducing the emissions of greenhouse gases (GHG) from paddy fields is crucial both for the sustainability of rice production and mitigation of global climatic warming. The effects of applying industrial and agricultural wastes as fertilizer on the reduction of GHG emissions in cropland areas, however, remain poorly known. We studied the effects of the application of 8 Mg ha−1 of diverse wastes on GHG emission and rice yield in a subtropical paddy in southeastern China. Plots fertilized with steel slag, biochar, shell slag, gypsum slag and silicate and calcium fertilizer had lower total global-warming potentials (GWP, including CO2, CH4 and N2O emissions) per unit area than control plots without waste application despite non-significant differences among these treatments. Structural equation models showed that the effects of these fertilization treatments on gas emissions were partially due to their effects on soil variables, such as soil water content or soil salinity. Steel slag, biochar and shell slag increased rice yield by 7.1%, 15.5% and 6.5%, respectively. The biochar amendment had a 40% lower GWP by Mg−1 yield production, relative to the control. These results thus encourage further studies of the suitability of the use waste materials as fertilizers in other different types of paddy field as a way to mitigate GHG emissions and increase crop yield.

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PENGARUH RESIDU PUPUK P PADA MT I TERHADAP STATUS P TANAH dan HASIL PADI SAWAH PADA MT II di KABUPATEN DHARMASRAYA SUMATERA BARAT Tinggi Di Kabupaten Dharmasya Sumatera Barat

Jurnal Pengkajian dan Pengembangan Teknologi Pertanian ◽

10.21082/jpptp.v21n1.2018.p63-72 ◽

2018 ◽

Vol 21 (1) ◽

pp. 63

Author(s):

Ismon Lenin

Keyword(s):

Paddy Field ◽

Rice Yield ◽

Soil Phosphorus ◽

Residual Effect ◽

High Rate ◽

Fertilizer Rate ◽

High Productivity ◽

P Fertilizer ◽

Planting Season ◽

Very High

ABSTRACT Effectof Residual Fertilizer P on MTI to Land P StatusandResults Paddy Fieldon MT II in District Dharmasraya West Sumatera. Upland converted to paddy field, and intensively fertilized for 30 years causes the soil phosphorus (P) to be very high and the plant does not respond to the fertilization of P. P fertilizer residues given in the previous planting season needs to be studied its utilization for the next planting. This study aimed to examine the effect of P fertilizer residue on MT I with high P status to P status and paddy rice yield on MT II in Dharmasraya Regency. The research was conducted from August - December 2013 on newly established paddy field in Dharmasraya District with Typic Hapludults soil type. The results showed that the application of P fertilizer at MT I with high rate on the high P status was proven to be utilized by plant on MT II. However, to obtain high productivity of the plant is still needed additional P fertilizer. The residue of P fertilizer on MT I can still be utilized to increase yield on MT II by 8.46% from 4,444 kg dried milled grain/ha to 4,820 kg dried milled grain/ha. The increase of P fertilizer rate no longer has a significant effect on the increase of dried grain yield. paddy, fertilizer,phosphorus, residual effect. ABSTRAKLahan kering yang dikonversi menjadi sawah, dan diberi pupuk secara intensif selama 30 tahun menyebabkan kadar hara fosfor (P) tanah menjadi sangat tinggi dan tanaman tidak respon terhadap pemupukan P. Residu pupuk P yang diberikan pada musim tanam sebelumnya perlu dikaji pemanfaatannya untuk tanaman berikutnya. Penelitian ini bertujuan untuk menguji pengaruh residu pupuk P pada MT I pada lahan sawah berstatus P tinggi terhadap status P tanah dan hasil padi sawah pada MT II di Kabupaten Dharmasraya. Penelitian dilaksanakan dari bulan Agustus - Desember 2013 pada sawah baru mapan di Kabupaten Dharmasraya dengan jenis tanah Typic Hapludults. Hasil pengkajian menunjukkan pemberian pupuk P pada MT I dengan dosis tinggi pada sawah dengan status P tinggi, terbukti masih bisa dimanfaatkan tanaman pada MT II. Namun demikian, untuk mendapatkan produktivitas tanaman yang tinggi masih diperlukan tambahan pupuk P. Residu pupuk P pada MT I masih dapat dimanfaatkan untuk meningkatkan hasil pada MT II sebesar 8,46% dari 4.444 kg GKG/ha menjadi 4.820 kg GKG/ha. Peningkatan takaran pupuk P selanjutnya tidak lagi berpengaruh nyata terhadap peningkatan hasil gabah kering giling. padi sawah, pemupukan, fosfor, pengaruh residu.

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The Effect of Rice Bug Population (Leptocorisa oratorius Fabricius) on Paddy Yield in Kimak Village, Merawang District, Bangka Regency

AGROSAINSTEK Jurnal Ilmu dan Teknologi Pertanian ◽

10.33019/agrosainstek.v2i1.19 ◽

2018 ◽

Vol 2 (1) ◽

pp. 6-14

Author(s):

Winarsi Winarsi ◽

Sitti Nurul Aini ◽

Rion Apriyadi

Keyword(s):

Experimental Method ◽

Paddy Field ◽

Yield Loss ◽

Rice Yield ◽

Staple Food ◽

Randomized Design ◽

Rice Bug ◽

Completely Randomized Design ◽

Leptocorisa Oratorius ◽

Paddy Yield

Rice crops are the main source of staple food for the Indonesian people, as well as in the Bangka Belitung province. The cultivation of rice crops is still through various obstacles, such as the attack of Leptocorisa oratorius Fabricius, which attacks the rice plants after flowering by sucking the grain. The aim of this study was to know the effect of L.oratorius population on the rice yield, to know the number of L. oratorius that can decrease the 15% paddy yield and to know the percentage of rice loss based on the number of L. oratorius population in the Kimak village, Merawang district, Bangka regency. The research was conducted on November 2017 to January 2018 on paddy field in Kimak village. This research used experimental method with Completely Randomized Design (CRD) wich consist of 8 treatments and 2 replications. The treatment was the differences L.oratorius population. Consist of: without L.oratorius, 2 L.oratorius, 3 L.oratorius, 4 L.oratorius, 5 L.oratorius, 6 L.oratorius, 7 L.oratorius and 8 L.oratorius. The result showed that the number of L. oratorius has significant effect on rice yield, 3 population of L. oratorius per 50 cm x 50 cm able to reduce the rice yield by 15% and the percentage of yield loss at the treatment of 2 - 8 L.oratorius is about 10.97% up to 28.98%.

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