At macro level, all three states in peninsular India showed a continued yield increase in kharif and rabi rices over the 18-year period. Growth rates varied from very low in Karnataka and Andhra Pradesh to moderately high in Tamil Nadu (Table 15). The linear growths of kharif and rabi rice yields, as well as system productivity, were highly significant, with rabi rice showing higher yield increment than kharif rice in Tamil Nadu and Andhra Pradesh; in Karnataka the difference was insignificant. The increase in both states was due to impressive growth achieved during the 1980s. In the 1990s, the growth trends of both seasons' rices were negative in Tamil Nadu and Andhra Pradesh, and moderately high in kharif in Karnataka. A probable explanation of the differences is that in Tamil Nadu and Andhra Pradesh there was a higher pace of adoption of high-yielding varieties from the early 1970s (resulting in higher growth in the 1970s and 1980s, peaking in the 1990s), than in Karnataka during that period.
TABLE 15
Yield growth (kg/ha) of kharif and rabi rice under rice-rice cropping system in selected states of peninsular India, 1981/82-1997/98
Andhra Pradesh |
Tamil Nadu |
Karnataka | ||||||||
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total | ||
Crop growth rate (1981-98) |
0.95 |
1.67 |
1.34 |
2.06 |
2.69 |
2.40 |
-0.09 |
0.30 |
0.52 | |
Crop growth rate (1981-90) |
2.37 |
2.76 |
2.59 |
6.18 |
5.25 |
5.72 |
0.13 |
-1.00 |
-0.53 | |
Crop growth rate (1990-98) |
-0.59 |
-0.52 |
-0.55 |
-2.66 |
-0.35 |
-1.44 |
2.36 |
0.42 |
2.98 | |
Mean (1981-83) |
3 095 |
3 440 |
6 534 |
3 091 |
3 117 |
6 207 |
2 777 |
3 997 |
6 775 | |
Mean (1988-90) |
3 581 |
4 207 |
7 789 |
4 542 |
4 273 |
8 816 |
2 889 |
3 806 |
6 695 | |
Mean (1990-92) |
3 577 |
4 386 |
7 963 |
4 629 |
4 731 |
9 359 |
3 015 |
3 864 |
6 878 | |
Mean (1996-98) |
3 483 |
4 083 |
7 566 |
3 704 |
4 606 |
8 311 |
3 407 |
4 052 |
7 460 | |
% increase 11 |
15.73 |
22.32 |
19.20 |
46.96 |
37.11 |
42.02 |
4.03 |
-4.79 |
-1.17 | |
%increase 22 |
-2.62 |
-6.90 |
-4.98 |
-19.97 |
-2.63 |
-11.20 |
13.02 |
4.88 |
8.45 | |
% increase T3 |
12.55 |
18.72 |
15.80 |
19.85 |
47.80 |
33.88 |
22.68 |
1.38 |
10.11 | |
Contribution %4 |
91.8 |
96.0 |
- |
94.5 |
94.5 |
- |
89.0 |
82.0 |
- | |
1% increase 1= percentage increase of mean (1988-90) over mean (1981-83).
2% increase 2= percentage increase of mean (1996-98) over mean (1990-92).
3% increase T= percentage increase of mean (1996-98) over mean (1981-83).
4Contribution % = variation percentage in the rice-rice system yield explained by the season yield independently.
At district level also, yield increases ranging from moderate to high in kharif and rabi rice were observed across the three states, except West Godavari in Andhra Pradesh and Mandya in Karnataka (Table 16). In the 1990s, however, the yield level and growth rate of both kharif and rabi rice declined to very low levels in Tamil Nadu and Andhra Pradesh, with Mandya District in Karnataka still showing signs of positive growth because of impressive growth in rabi rice. Kanyakumari District in Tamil Nadu, which receives southwest as well as northeast monsoons, demonstrated high yield growth in both the seasons. The system productivity growth was uniformly low: the growth was either slightly positive (as in Andhra Pradesh, Karnataka, and Kanyakumari and Tirunelveli districts in Tamil Nadu) or negative (as in most of the districts in Tamil Nadu). There is little scope for an appreciable yield increase in Tamil Nadu, as is clear from the low-to-negative growth and the very narrow yield gap known to exist (15 percent). There is considerably more scope for Andhra Pradesh, with its sizeable yield gap, to raise its yield levels of kharif and rabi rice.
TABLE 16
Yield growth (kg/ha) of kharif and rabi rice system in selected districts of peninsular India, 1981/82-1997/98
Andhra Pradesh | ||||||||||||
West Godavari |
Kurnool |
Nellore | ||||||||||
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total | ||||
Crop growth rate (1981-98) |
-0.67 |
1.81 |
0.82 |
3.68 |
1.14 |
2.41 |
2.27 |
3.29 |
2.72 | |||
Crop growth rate (81-90) |
-3.44 |
1.99 |
0.11 |
3.58 |
-1.41 |
0.94 |
4.91 |
6.30 |
5.46 | |||
Crop growth rate (1990-98) |
-0.55 |
0.55 |
0.31 |
3.40 |
-0.78 |
1.43 |
2.12 |
1.91 |
2.04 | |||
Mean (1981-83) |
3 688 |
4 496 |
8 184 |
2 741 |
3 293 |
6 034 |
3 148 |
2 210 |
5 358 | |||
Mean (1988-90) |
2 776 |
5 437 |
8 212 |
3 399 |
3 009 |
6 408 |
4 169 |
3 421 |
7 590 | |||
Mean (1990-92) |
2 997 |
5 258 |
8 255 |
3 770 |
4 113 |
7 883 |
3 489 |
3 703 |
7 192 | |||
Mean (1996-98) |
2 956 |
5 495 |
8 451 |
4 957 |
3 800 |
8 757 |
4 051 |
4 324 |
8 375 | |||
% increase 11 |
-24.7 |
20.9 |
0.4 |
24.0 |
-8.6 |
6.2 |
32.4 |
54.8 |
41.7 | |||
% increase 22 |
-1.4 |
4.5 |
2.4 |
31.5 |
-7.6 |
11.1 |
16.1 |
16.8 |
16.5 | |||
% increase T3 |
-19.9 |
22.2 |
3.3 |
80.8 |
15.4 |
45.1 |
28.7 |
95.7 |
56.3 | |||
Tamil Nadu | ||||||||||||
Tanjavur |
Tiruchirapalli |
Tiruneveli | ||||||||||
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total | ||||
Crop growth rate (1981-98) |
4.12 |
2.37 |
3.34 |
3.92 |
2.37 |
3.23 |
4.63 |
4.67 |
4.63 | |||
Crop growth rate (1981-90) |
5.65 |
6.57 |
6.04 |
10.05 |
8.71 |
9.44 |
5.93 |
4.69 |
5.37 | |||
Crop growth rate (1990-98) |
-0.77 |
-4.40 |
-2.43 |
-2.34 |
-4.30 |
-3.21 |
0.50 |
0.77 |
0.62 | |||
Mean (81-83) |
3 423 |
2 813 |
6 235 |
3 062 |
2 835 |
5 897 |
3 746 |
2 985 |
6 731 | |||
Mean (88-90) |
4 751 |
4 050 |
8 801 |
5 854 |
4 619 |
10 472 |
5 583 |
4 050 |
9 633 | |||
Mean (1990-92) |
5 480 |
5 133 |
10 613 |
6 170 |
5 123 |
11 294 |
5 876 |
5 192 |
11 068 | |||
Mean (1996-98) |
5 445 |
3 668 |
9 113 |
5 618 |
4 657 |
10 275 |
6 123 |
5 551 |
11 675 | |||
% increase 11 |
38.8 |
44.0 |
41.2 |
91.2 |
62.9 |
77.6 |
49.0 |
35.7 |
43.1 | |||
% increase 22 |
-0.6 |
-28.5 |
-14.1 |
-9.0 |
-9.1 |
-9.0 |
4.2 |
6.9 |
5.5 | |||
% increase T3 |
59.1 |
30.4 |
46.2 |
83.5 |
64.3 |
74.2 |
63.4 |
86.0 |
73.4 | |||
Tamil Nadu |
Karnataka | |||||||||||
Kanya Kumari |
Mandya |
Shimoga | ||||||||||
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total | ||||
Crop growth rate (81-98) |
5.41 |
5.10 |
5.24 |
-0.34 |
1.25 |
0.48 |
1.51 |
0.07 |
0.35 | |||
Crop growth rate (81-90) |
3.03 |
-3.80 |
0.25 |
-1.48 |
0.58 |
-0.43 |
1.36 |
-0.92 |
0.00 | |||
Crop growth rate (1990-98) |
5.67 |
2.77 |
4.11 |
-0.15 |
3.61 |
1.66 |
- |
- |
- | |||
Mean (81-83) |
3 364 |
3 300 |
6 664 |
4 432 |
4 281 |
8 713 |
2 592 |
4 297 |
6 889 | |||
Mean (88-90) |
5 070 |
2 550 |
7 620 |
4 049 |
4 695 |
8 744 |
2 867 |
4 202 |
7 069 | |||
Mean (1990-92) |
4 457 |
5 361 |
9 818 |
4 081 |
4 167 |
8 248 |
3 118 |
4 012 |
7 130 | |||
Mean (1996-98) |
5 991 |
5 889 |
11 880 |
4 027 |
5 034 |
9 061 |
- |
- |
- | |||
% increase 11 |
50.7 |
-22.7 |
14.3 |
-8.6 |
9.7 |
0.4 |
10.6 |
-2.2 |
2.6 | |||
% increase 22 |
34.4 |
9.8 |
21.0 |
-1.3 |
20.8 |
9.9 |
- |
- |
- | |||
% increase T3 |
78.1 |
78.4 |
78.3 |
-9.1 |
17.6 |
4.0 |
- |
- |
- | |||
1% increase 1 = percentage increase of mean (1988-90) over mean (1981-83).
2% increase 2 = percentage increase of mean (1996-98) over mean (1990-92).
3% increase T = percentage increase of mean (1996-98) over mean (1981-83).
At micro level, the yield trend for both kharif and rabi season rice showed very low to negative growth at most seed farms in Andhra Pradesh (all except three in rabi and one in kharif), which incidentally can be categorized as being in a low-to-medium yield environment (Tables 17-21). In farmers' fields, the growth of rabi rice was uniformly very high, unlike the kharif rice, where the growth rate varied from low to high depending on the farm. In Tamil Nadu, yield growth was uniformly very low positive for both kharif and rabi rices at all the seed farms and farmers' fields, confirming the trend observed by state- and district-level analysis.
TABLE 17
Yield growth (kg/ha) of kharif and rabi rice in selected seed farms under the rice-rice system in Andhra Pradesh, 1991/92-1997/98
Samalkot (EG) |
Garikapadu (Krishna) |
Undi (WG) |
Kanekal (Anantapur) | ||||||||||||
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total | ||||
Crop growth rate |
-3.56 |
-6.48 |
-5.02 |
-4.74 |
6.10 |
-0.34 |
0.68 |
3.13 |
1.91 |
2.25 |
-3.59 |
-1.17 | |||
Mean (1991-93) |
4 591 |
4 771 |
9 362 |
4 141 |
2 712 |
6 853 |
3 715 |
3 405 |
7 120 |
3 042 |
4 401 |
7 442 | |||
Mean (1996-98) |
4 485 |
4 056 |
8 541 |
3 319 |
3 431 |
6 750 |
3 990 |
4 130 |
8 120 |
2 908 |
3 466 |
6 374 | |||
% increase |
-2.31 |
-15.00 |
-8.77 |
-19.85 |
26.49 |
-1.51 |
7.40 |
21.29 |
14.04 |
-4.41 |
-21.24 |
-14.36 | |||
Palampeta (Warangal) |
ARS (Nellore) |
ARS (Maruteru, WG)) | |||||||||
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total | |||
Crop growth rate |
-2.26 |
5.35 |
1.89 |
0.50 |
-0.41 |
0.01 |
-2.52 |
1.44 |
-0.20 | ||
Mean (1991-93) |
2 681 |
2 820 |
5 501 |
5 750 |
5 398 |
11 148 |
5 000 |
6 000 |
11 000 | ||
Mean (1996-98) |
2 527 |
3 510 |
6 037 |
5 905 |
5 418 |
11 323 |
4 250 |
6 500 |
10 750 | ||
% increase |
-5.73 |
24.47 |
9.75 |
2.70 |
0.37 |
1.57 |
-15.00 |
8.33 |
-2.27 | ||
TABLE 18
Yield growth (kg/ha) of kharif and rabi rice in selected on-farm trials under the rice-rice system in West Godavari and Nellore, 1991/93-1996/98
|
West Godavari | |||||||||||||||
|
Eletipadu 1 |
Eletipadu 2 |
CV Palem 1 |
CV Palem 2 | ||||||||||||
|
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total | ||||
Crop growth rate |
-2.68 |
4.60 |
1.58 |
-7.33 |
4.60 |
-0.45 |
-3.94 |
4.53 |
1.12 |
-2.04 |
4.37 |
1.54 | |||
Mean (1991-93) |
5 125 |
6 375 |
11 500 |
5 625 |
6 375 |
12 000 |
5 125 |
6 875 |
12 000 |
5 625 |
6 375 |
12 000 | |||
Mean (1996-98) |
4 650 |
7 625 |
12 275 |
4 125 |
7 625 |
11 750 |
4 500 |
8 250 |
12 750 |
5 125 |
7 750 |
12 875 | |||
% increase |
-9.27 |
19.61 |
6.74 |
-26.67 |
19.61 |
-2.08 |
-12.20 |
20.00 |
6.25 |
-8.89 |
21.57 |
7.29 | |||
|
West Godavari | |||||||||||||||
|
Kaikaram 1 |
Poduru 1 |
Poduru 2 |
Kavitam 1 | ||||||||||||
|
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total | ||||
Crop growth rate |
2.14 |
4.99 |
3.68 |
2.88 |
5.28 |
4.22 |
2.85 |
4.31 |
3.77 |
0.23 |
4.30 |
2.53 | |||
Mean (1991-93) |
5 875 |
7 025 |
12 900 |
4 875 |
6 150 |
11 025 |
5 300 |
6 275 |
11 575 |
5 875 |
6 600 |
12 475 | |||
Mean (1996-98) |
6 350 |
8 225 |
14 575 |
5 300 |
7 625 |
12 925 |
6 225 |
7 500 |
13 725 |
6 350 |
7 725 |
14 075 | |||
% increase |
8.09 |
17.08 |
12.98 |
8.72 |
23.98 |
17.23 |
17.45 |
19.52 |
18.57 |
8.09 |
17.05 |
12.83 | |||
|
West Godavari | |||||||||||||||
|
Kavitam 2 |
Rajula Peta |
Kaikaram 2 |
Akiveedu | ||||||||||||
|
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total | ||||
Crop growth rate |
2.65 |
5.65 |
4.41 |
4.46 |
3.18 |
3.85 |
0.64 |
2.74 |
1.86 |
1.19 |
3.66 |
2.61 | |||
Mean (1991-93) |
5 425 |
6 400 |
11 825 |
4 875 |
6 150 |
11 025 |
5 900 |
6 750 |
12 650 |
5 625 |
6 275 |
11 900 | |||
Mean (1996-98) |
6 350 |
7 725 |
14 075 |
6 075 |
6 875 |
12 950 |
6 375 |
7 650 |
14 025 |
6 350 |
7 250 |
13 600 | |||
% increase |
17.05 |
20.70 |
19.03 |
24.62 |
11.79 |
17.46 |
8.05 |
13.33 |
10.87 |
12.89 |
15.54 |
14.29 | |||
|
Nellore | |||||||||||||||||||
|
Kakulapadu |
Gangapatnam |
Pottepalem |
Yallayapalem |
Peddacherukuru | |||||||||||||||
|
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total | |||||
Crop growth rate |
5.92 |
3.30 |
4.66 |
1.81 |
2.15 |
1.97 |
2.91 |
3.00 |
2.95 |
1.37 |
1.07 |
1.22 |
4.05 |
4.16 |
4.11 | ||||
Mean (1991-93) |
4 500 |
4 200 |
8 700 |
5 750 |
4 900 |
10 650 |
5 450 |
4 650 |
10 00 |
5 250 |
4 700 |
9 950 |
5 250 |
4 750 |
10 000 | ||||
Mean (1996-98) |
5 750 |
5 000 |
10 750 |
6 250 |
5 400 |
11 650 |
6 100 |
5 200 |
11 300 |
5 500 |
4 900 |
10 400 |
6 100 |
5 500 |
11 600 | ||||
% increase |
27.78 |
19.05 |
23.56 |
8.70 |
10.20 |
9.39 |
11.93 |
11.83 |
11.88 |
4.76 |
4.26 |
4.52 |
16.19 |
15.79 |
16.00 | ||||
TABLE 19
Yield growth (kg/ha) of kharif and rabi rice in selected seed farms under the rice-rice system in Tamil Nadu
|
TRRI, Aduthurai |
Thirunelveli |
Tanjore | |||||||||
|
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total | |||
Crop growth rate |
1.73 |
1.89 |
2.88 |
38.89 |
7.22 |
25.94 |
-1.72 |
-1.44 |
-1.59 | ||
Mean (1992-93) |
5 808 |
3 235 |
8 290 |
- |
1 713 |
- |
4 663 |
4 217 |
8 879 | ||
Mean (1997-98) |
6 358 |
3 062 |
9 419 |
- |
2 858 |
- |
4 420 |
4 128 |
8 547 | ||
% increase |
9.5 |
-5.4 |
13.6 |
- |
66.9 |
- |
-5.2 |
-2.1 |
-3.7 | ||
|
Kanyakumari |
Trichy |
Theni | |||||||||
|
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total | |||
Crop growth rate |
-2.47 |
-10.37 |
-6.29 |
- |
3.05 |
- |
-0.21 |
2.26 |
0.99 | ||
Mean (1992-93) |
3 559 |
3 918 |
7 477 |
- |
3 481 |
- |
4 202 |
3 870 |
8 072 | ||
Mean (1997-98) |
3 368 |
2 274 |
5 642 |
- |
3 422 |
- |
4 162 |
4 212 |
8 373 | ||
% increase |
-5.4 |
-42.0 |
-24.5 |
- |
-1.7 |
- |
-1.0 |
8.8 |
3.7 | ||
TABLE 20
Yield growth (kg/ha) of karif and rabi rice in selected on-farms under the rice-rice system in Tamil Nadu
|
Tanjavur | |||||||||||||||||
|
Ammenpettai 1 |
Ammenpettai 2 |
Thirumangalakudi |
Thiruvisanalluru |
Thugili | |||||||||||||
|
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total | |||
Crop growth rate |
-3.13 |
-3.12 |
- |
-4.89 |
- |
- |
-3.42 |
-5.52 |
- |
5.08 |
-1.35 |
- |
3.51 |
-0.95 |
- | ||
Mean (1995-96) |
6 566 |
5 248 |
- |
5 350 |
- |
- |
6 302 |
5 643 |
- |
5 220 |
4 813 |
- |
5 230 |
4 814 |
- | ||
Mean (1999-00) |
5 675 |
5 041 |
- |
4 746 |
- |
- |
5 579 |
4 971 |
- |
6 320 |
4 666 |
- |
5 594 |
4 515 |
- | ||
% increase |
-13.58 |
-3.94 |
- |
-11.30 |
- |
- |
-11.47 |
-11.91 |
- |
21.07 |
-3.04 |
- |
6.96 |
-6.22 |
- | ||
|
Tanjavur |
Nagapattinam | |||||||||||||||||
|
Koranattukarpur |
Tirumannachery |
Therazhandur 1 |
Therazhandur 2 |
Kshetirabalapuram | ||||||||||||||
|
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total | ||||
Crop growth rate |
-3.44 |
-2.85 |
- |
2.49 |
4.82 |
- |
2.82 |
-0.27 |
- |
3.10 |
-4.09 |
- |
-2.70 |
2.42 |
- | |||
Mean (1995-96) |
6 337 |
5 339 |
- |
5 930 |
4 185 |
- |
5 986 |
5 146 |
- |
5 332 |
4 298 |
- |
6 516 |
4 213 |
- | |||
Mean (1999-00) |
5 592 |
5 126 |
- |
6 346 |
4 689 |
- |
6 584 |
5 174 |
- |
5 733 |
3 788 |
- |
6 006 |
4 238 |
- | |||
% increase |
-11.76 |
-3.99 |
- |
7.02 |
12.04 |
- |
9.99 |
0.54 |
- |
7.53 |
-11.86 |
- |
-7.83 |
0.61 |
- | |||
TABLE 21
Yield growth (tonnes/ha) of kharif and rabi rice in selected seed farms and on-farm trials under the rice-rice system in Karnataka
|
Seed farm, RRS Mandya |
On-farm trials, Mandya | |||||||||
|
Sivalli |
VC farm |
EEI, RRS, Mandya |
Sampalli | |||||||
|
Kharif |
Rabi |
Kharif |
Kharif |
Rabi |
Kharif |
Rabi |
Total | |||
Crop growth rate |
-0.74 |
0.37 |
6.51 |
2.97 |
5.58 |
10.03 |
8.27 | |||
Mean (1991-93) |
3.60 |
3.31 |
4.00 |
2.85 |
4.40 |
3.15 |
3.50 |
6.65 | ||
Mean (1997-99) |
3.43 |
4.03 |
4.14 |
3.85 |
5.00 |
3.90 |
5.35 |
9.25 | ||
% increase |
-4.5 |
21.6 |
3.5 |
35.1 |
13.6 |
23.8 |
52.9 |
39.1 | ||
Overall, the study at macro and micro levels in peninsular India shows that Tamil Nadu (with the exception of Kanyakumari District and a few pockets in Nagapatinarn District) has reached a kind of yield threshold, beyond which appreciable yield increase may not be possible. Although Andhra Pradesh is also fast approaching a similar yield threshold, certain regions and pockets still exist with prospects for sizeable yield growth through the adoption of improved crop management strategies. As in Punjab, further yield increases in Tamil Nadu have to come from the introduction of varietal technologies with a decidedly higher ceiling to present genetic yield. The adoption of higher-yielding hybrids might help to raise the yield level further.
Long-term experiments underway since the 1970s to assess the performance of crop and system sustain-ability at constant levels of fertilizer application revealed, in general, the yield growth of kharif rice to be static at a very low level (-0.38 percent). In contrast, rabi rice yields increased significantly with a moderately high growth rate (2.65 percent) between 1989 and 1999 in Godavari Delta Region (Maruteru) in Andhra Pradesh and Cauvery Delta (Thanjavur) in Tamil Nadu. These findings confirm the limited scope for improving the yield level of kharif rice in the traditional rice deltas using currently available varietal and crop production technologies (Table 22). Findings from Nandyal (Table 23) and Hyderabad centres in Andhra Pradesh (Table 24), however, suggest there is scope to enhance the yield level of kharif rice in parts of Rayalaseema and Telengana. In the Godavari Delta region, the adoption of integrated nutrient management has been found to help increase system productivity: the yield level of monsoon rice in Bhubaneswer (Orissa) progressed from a moderate decline to a substantial increase with supplementary farmyard manure (Table 25). The decline could also be caused by incipient deficiency of sulphur following continuous use of sulphur-free fertilizer sources (Nambiar, 1995).
TABLE 22
Yield growth (tonnes/ha) of rice in long-term farm experiments (DRR) under the rice-rice system in Maruteru, Andhra Pradesh
|
Treatment 11 |
Treatment 22 | |||
|
Kharif |
Rabi |
Kharif |
Rabi | |
Crop growth rate |
-0.38 |
2.65 |
1.35 |
4.60 |
Initial yield |
3.40 |
4.40 |
2.92 |
3.60 |
Final yield |
3.59 |
6.41 |
3.33 |
6.01 |
% increase |
5.59 |
45.68 |
14.04 |
66.94 |
R |
-0.04ns |
0.60ns |
0.11ns |
0.94** |
B |
-0.02 |
0.14 |
0.04 |
0.21 |
A |
5.09 |
4.66 |
4.14 |
3.65 |
1Treatment 1: 100% NPK.
2Treatment 2: 50% NPK + 50% N.
TABLE 23
Yield growth (kg/ha) of rice in long-term farm experiments (AICARP) under the rice-rice system
|
ARS (Nandyal, Krishna) |
ARS (Tanjore, Tamil Nadu) | |||||
|
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total | |
Crop growth rate |
3.69 |
3.05 |
3.35 |
-0.25 |
6.00 |
2.22 |
Mean (1976-78) |
3 590 |
3 655 |
7 245 |
5 795 |
3 420 |
9 215 |
Mean (1981-83) |
4 300 |
4 415 |
8 715 |
5 550 |
4 175 |
9 725 |
% increase |
19.78 |
20.79 |
20.29 |
-4.23 |
22.08 |
5.53 |
TABLE 24A
Yield growth (tonnes/ha) of kharif rice under the rice-rice system in long-term farm experiments (DRR), 1990-991
|
0 |
N |
NP |
NPK |
NPKZn |
NPKZn-S | |
Mean (initial) |
2.03 |
3.84 |
4.11 |
4.47 |
4.49 |
4.31 |
Mean (final) |
2.76 |
3.78 |
3.96 |
4.15 |
4.63 |
4.23 |
% increase (1/8) |
35.96 |
-1.56 |
-3.65 |
-7.16 |
3.12 |
-1.86 |
Crop growth rate |
9.35 |
1.55 |
1.22 |
-0.33 |
1.01 |
-0.16 |
1Figures are three-year moving averages.
N - 150 kg/ha; P - 90 kg P2O5/ha; K - 90 kg K2O/ha; Zn - 40 kg ZnSO4/ha.
TABLE 24B
Yield growth (tonnes/ha) of rabi rice under rice-rice system in long-term farm experiments (DRR), 1990-971
|
0 |
N |
NP |
NPK |
NPKZn |
NPKZn-S | |
Mean (initial) |
2.02 |
5.70 |
6.02 |
6.37 |
6.36 |
5.92 |
Mean (final) |
2.28 |
4.51 |
4.31 |
5.12 |
5.35 |
5.30 |
% increase (1/6) |
12.87 |
-20.88 |
-28.41 |
-19.62 |
-15.88 |
-10.47 |
Crop growth rate |
3.10 |
-3.56 |
-5.67 |
-2.86 |
-2.01 |
-0.83 |
1Figures are three-year moving averages.
N - 150 kg/ha; P - 90 kg P2O5/ha; K - 90 kg K2O; Zn - 40 kg ZnSO4/ha.
TABLE 25
Yield growth (q/ha)1 of kharif and rabi rice in long-term farm experiements in Bhubaneswer
|
Treatment 12 |
Treatment 23 | |||
|
Kharif |
Rabi |
Kharif |
Rabi | |
Mean (1973-75) |
24.45 |
28.24 |
26.83 |
33.63 |
Mean (1992-94) |
21.17 |
25.88 |
34.17 |
36.76 |
% increase (1/8) |
-25.05 |
-5.41 |
20.53 |
7.93 |
Crop growth rate |
-1.03 |
-0.55 |
1.09 |
0.44 |
r |
-0.32ns |
-0.23ns |
0.38ns |
0.21ns |
r2 |
0.104976 |
0.05482105 |
0.143641 |
0.0452011 |
1 1 q= 100 kg.
2 Treatment 1 - 100% NPK.
3 Treatment 2 - 100% NPK + farmyard manure.
