Uji Kalibrasi Nitrogen pada Tiga Tanah Tropika Masam di Jawa Barat
Summary
Zulhadia. Calibration test of nitrogen on three acid tropical soils in West Java (under
supervision of Untung Sudadi and F.M. Leiwakabessy).
This Study is a part of program series on the establishment and development of N, P,
and K fertilizer recommendation for dry land food crops (dry land rice, corn, and
soybean) on acit tropical soils based on soil and crop characteristics. Results of the
preceding correlation study showed that the use of N-Kjeldahl and C-Walkley&Black
extraction method - to determine, respectively, soil total nitrogen and organic carbon
or organic matter - gave a sigiificant correlation with nitrogen absorption of the test
plant. The content of soil organic-C can be used to estimate the availability of soil
nitrogen since almost all of the soil nitrogen is found in the fonn of organic
compounds.
In this study, a calibratoin test between the availability status of soil nitrogen
based on the result of N-Kjeldahl and C-Walkley&Black extraction procedure and the
relative yield percentage of corn was carried out. The objectives were to determine
agronomic value of the analytical result of N-Kjeldahl and C-Walkley&Black
extraction procedures to measure the soil N availability for corn on acid tropical soils
through calibration test in the field. The calibration test procedure to be evaluated
were Cate-Nelson graphical method and relative yield percentage method based on
Coupe and Rouse criteria (1973).
The field experiment was carried out on three locations, i.e. Latosol Darmaga
(Dystropept), Latosol Gunung Sindur (Dystropept), and Podsolik Guradok
(tropudults). To build a wide range of soil N availability, four incubation blocks (A,
B, C, and D) were set in each location with 0, 10, 20, and 30 ton organic matterlha,
respectively. The basal treatment given were 75 kg PzOjIha (208.5 kg SP-36/ha) and
75 kg KzO/ha ( 1 25.1 kg KCLIha) as well application of lime at a dose of 2080, 2750
and 14 411 kg CaC0;Iha for Dannaga, Gunung Sindur and Guradok soils,
respectively. The experimental design performed in each location was randomized
block d e s i g with4levels of N fertilizer application (0, 50, 100, and 150 k ~ h a as
)
the treatments and 3 replications as the block.
From the Cate-Nelson graph, it is found that the critical limits \\(ere 0,34% for
N-Kjeldahl and 3,4% for C-Walkley&Black. By excluding data in quadrant I1 and IV
of the Cate-Nelson graph, the use of relative yield percentage procedure based on the
criteria of Coupe and Rouse (1973) gave the soil C-WalkleyPcBlack availability
criteria as the following: low (4.2%), while
for N-Kjeldahl were: low (0.33%), medium (0.33-0.42%), and high (>0.32%). Based
on these criteria, the N, as well as organic-C contents of the soils studied in all blocks
was categorized as low, except for Latosol Dannaga Block D which was low.
The predicted corn grain dry yield (Y) using C-Walkley&Black (Xi) and N
fertilizer dose (Xz) data as the free variables fallows equations: Y = 2300 + 556 Xi +
11.3 X2, R' = 58.8% for Darmaga location with low N availability class, Y = -1531 +
1743 XI + 5.05 X?.
-. R' = 94.0% for Darmaga location with medium class, Y = -1 130
+ 1510 XI + 34.6 X2 - 0.148 x'', R' = 56.5% for Gunung Sindur location, and Y = 2215 + 1372 XI + 34.6 Xz- 0.148 X; ,R' = 55.5% for guradok location.
. The predicated corn g a i n dry yield (Y) using N-Kjeldahl (XI) and N
fertilizer dose (X2)data as the free variables fallows equations: Y = 2496 + 4976 XI +
11.3 Xz, R' = 55.7% for Darmaga location with low N availability class, Y = -869566
+ 4723008 XI + 5.05 X? - 6369167 XI' , R' = 95.6% for Darmaga location with
lnediuln class, Y = -205 + 10446 XI + 34.6 X? - 0.148 XZ' , R' = 54.8% for Gunung
Sindur location, and Y = -144 + 17024 XI + 7.86 Xz - 16477 XI' , R' = 31.8% for
guradok location.
Zulhadia. Uji Kalibrasi Nitrogen pada Tiga Tanah Tropika Masam di Jawa Barat
(Dibawah bilnbingan Untung Sudadi dan F.M. Leiwakabessy).
Penelitian ini merupakan rangkaian dari program penyusunan dan
pengembangan rekolnendasi pemupukan N, P dan K untuk tanaliian pangan lahan
kering (padi ladang, jagung dan kedelai) pada tanah tropika inasam yang didasarkan
pada karakteristik tanah dan tanaman. Hasil penelitian korelasi yang telah dilakukan
sebelumnya menunjukkan bahwa periggunaan metode ekstraksi N-Kjeldahl dan CWalkley&Black -masing-masing untuk menetapkan N-total dan C-organik atau bahan
organik tanah- berkorelasi baik dengan penyerapan N oleh tanaman uji jagung. Kadar
C-organik dapat digunakan sebagai penduga ketersediaan N-tanah karena sebagian
besar N-tanah berada dalam bentuk N-organik.
Pada penelitian ini dilakukan uji kalibrasi antara tingkat ketersediaan N-tanah
berdasarkan hasil ekstraksi N-Kjeldahl dan C-Walkley&Black dengan persen
produksi relatif jagung. Tujuan penelitian adalah lnenentukan nilai agronomik hasil
analisis tanah mengbwnakan metode ekstraksi N-Kjeldahl dan C-Walkley&Black
untuk lnengukur ketersediaan N-tanah bagi tananian uji jagung pada tanah-tanah
tropika lnasaln lnelalui uji kalibrasi. Metode uji kalibrasi yang dievaluasi adalah
metode grafik Cate-Nelson dan metode persen produksi relatif berdasarkan kriteria
Cope dan Rouse (1973).
Penelitian dilakukan di lapangan pada Latosol Dannaga (Dystropept), Latosol
Gunung Sindur (Dystropept) dan Podsolik Guradok (Tropudults). Untuk lnemperoleh
selang ketersediaan N-tanah yang lebar, di setiap lokasi dibuat 4 blok inkubasi bahan
organik (blok A, B, C dan D), masing-masing dengan taraf 0, 10, 20 dan 30 toniha.
Untuk pupuk dasar diberikan 75 kg P20j/ha (208.5 kg SP-36lha) dan 75 kg I
Zulhadia. Calibration test of nitrogen on three acid tropical soils in West Java (under
supervision of Untung Sudadi and F.M. Leiwakabessy).
This Study is a part of program series on the establishment and development of N, P,
and K fertilizer recommendation for dry land food crops (dry land rice, corn, and
soybean) on acit tropical soils based on soil and crop characteristics. Results of the
preceding correlation study showed that the use of N-Kjeldahl and C-Walkley&Black
extraction method - to determine, respectively, soil total nitrogen and organic carbon
or organic matter - gave a sigiificant correlation with nitrogen absorption of the test
plant. The content of soil organic-C can be used to estimate the availability of soil
nitrogen since almost all of the soil nitrogen is found in the fonn of organic
compounds.
In this study, a calibratoin test between the availability status of soil nitrogen
based on the result of N-Kjeldahl and C-Walkley&Black extraction procedure and the
relative yield percentage of corn was carried out. The objectives were to determine
agronomic value of the analytical result of N-Kjeldahl and C-Walkley&Black
extraction procedures to measure the soil N availability for corn on acid tropical soils
through calibration test in the field. The calibration test procedure to be evaluated
were Cate-Nelson graphical method and relative yield percentage method based on
Coupe and Rouse criteria (1973).
The field experiment was carried out on three locations, i.e. Latosol Darmaga
(Dystropept), Latosol Gunung Sindur (Dystropept), and Podsolik Guradok
(tropudults). To build a wide range of soil N availability, four incubation blocks (A,
B, C, and D) were set in each location with 0, 10, 20, and 30 ton organic matterlha,
respectively. The basal treatment given were 75 kg PzOjIha (208.5 kg SP-36/ha) and
75 kg KzO/ha ( 1 25.1 kg KCLIha) as well application of lime at a dose of 2080, 2750
and 14 411 kg CaC0;Iha for Dannaga, Gunung Sindur and Guradok soils,
respectively. The experimental design performed in each location was randomized
block d e s i g with4levels of N fertilizer application (0, 50, 100, and 150 k ~ h a as
)
the treatments and 3 replications as the block.
From the Cate-Nelson graph, it is found that the critical limits \\(ere 0,34% for
N-Kjeldahl and 3,4% for C-Walkley&Black. By excluding data in quadrant I1 and IV
of the Cate-Nelson graph, the use of relative yield percentage procedure based on the
criteria of Coupe and Rouse (1973) gave the soil C-WalkleyPcBlack availability
criteria as the following: low (4.2%), while
for N-Kjeldahl were: low (0.33%), medium (0.33-0.42%), and high (>0.32%). Based
on these criteria, the N, as well as organic-C contents of the soils studied in all blocks
was categorized as low, except for Latosol Dannaga Block D which was low.
The predicted corn grain dry yield (Y) using C-Walkley&Black (Xi) and N
fertilizer dose (Xz) data as the free variables fallows equations: Y = 2300 + 556 Xi +
11.3 X2, R' = 58.8% for Darmaga location with low N availability class, Y = -1531 +
1743 XI + 5.05 X?.
-. R' = 94.0% for Darmaga location with medium class, Y = -1 130
+ 1510 XI + 34.6 X2 - 0.148 x'', R' = 56.5% for Gunung Sindur location, and Y = 2215 + 1372 XI + 34.6 Xz- 0.148 X; ,R' = 55.5% for guradok location.
. The predicated corn g a i n dry yield (Y) using N-Kjeldahl (XI) and N
fertilizer dose (X2)data as the free variables fallows equations: Y = 2496 + 4976 XI +
11.3 Xz, R' = 55.7% for Darmaga location with low N availability class, Y = -869566
+ 4723008 XI + 5.05 X? - 6369167 XI' , R' = 95.6% for Darmaga location with
lnediuln class, Y = -205 + 10446 XI + 34.6 X? - 0.148 XZ' , R' = 54.8% for Gunung
Sindur location, and Y = -144 + 17024 XI + 7.86 Xz - 16477 XI' , R' = 31.8% for
guradok location.
Zulhadia. Uji Kalibrasi Nitrogen pada Tiga Tanah Tropika Masam di Jawa Barat
(Dibawah bilnbingan Untung Sudadi dan F.M. Leiwakabessy).
Penelitian ini merupakan rangkaian dari program penyusunan dan
pengembangan rekolnendasi pemupukan N, P dan K untuk tanaliian pangan lahan
kering (padi ladang, jagung dan kedelai) pada tanah tropika inasam yang didasarkan
pada karakteristik tanah dan tanaman. Hasil penelitian korelasi yang telah dilakukan
sebelumnya menunjukkan bahwa periggunaan metode ekstraksi N-Kjeldahl dan CWalkley&Black -masing-masing untuk menetapkan N-total dan C-organik atau bahan
organik tanah- berkorelasi baik dengan penyerapan N oleh tanaman uji jagung. Kadar
C-organik dapat digunakan sebagai penduga ketersediaan N-tanah karena sebagian
besar N-tanah berada dalam bentuk N-organik.
Pada penelitian ini dilakukan uji kalibrasi antara tingkat ketersediaan N-tanah
berdasarkan hasil ekstraksi N-Kjeldahl dan C-Walkley&Black dengan persen
produksi relatif jagung. Tujuan penelitian adalah lnenentukan nilai agronomik hasil
analisis tanah mengbwnakan metode ekstraksi N-Kjeldahl dan C-Walkley&Black
untuk lnengukur ketersediaan N-tanah bagi tananian uji jagung pada tanah-tanah
tropika lnasaln lnelalui uji kalibrasi. Metode uji kalibrasi yang dievaluasi adalah
metode grafik Cate-Nelson dan metode persen produksi relatif berdasarkan kriteria
Cope dan Rouse (1973).
Penelitian dilakukan di lapangan pada Latosol Dannaga (Dystropept), Latosol
Gunung Sindur (Dystropept) dan Podsolik Guradok (Tropudults). Untuk lnemperoleh
selang ketersediaan N-tanah yang lebar, di setiap lokasi dibuat 4 blok inkubasi bahan
organik (blok A, B, C dan D), masing-masing dengan taraf 0, 10, 20 dan 30 toniha.
Untuk pupuk dasar diberikan 75 kg P20j/ha (208.5 kg SP-36lha) dan 75 kg I