Table 3. Mean yields [kg ha−1] of cotton, soybean and wheat, and total productivity per cycle and across four years (2007–2010) in the farming systems compared in central India.
Farming system | Crop | Total productivity of crop rotation | ||||||||
Seed cotton | SEM | Wheat 2 grains | SEM | Soybean grains | SEM | Wheat grains | SEM | Seed cotton + Wheat 2 grains + Soybean grains + Wheat grains | SEM | |
Cycle 1 (2007–2008) | ||||||||||
BIODYN | 2'047 c | 68 | - | - | 1'399 a | 158 | 2'997 c | 153 | 6'443 b | 104 |
BIOORG | 2'072 c | 49 | - | - | 1'536 a | 192 | 2'831 c | 121 | 6'440 b | 187 |
CON | 2'700 b | 141 | - | - | 1'483 a | 155 | 4'262 a | 221 | 8'444 a | 146 |
CONBtC | 3'133 a | 176 | - | - | 1'473 a | 195 | 3'730 b | 272 | 8'336 a | 254 |
Cycle 2 (2009–2010) | ||||||||||
BIODYN | 1'894 a | 108 | - | - | 1'807 ab | 87 | 3'338 a | 207 | 7'039 b | 268 |
BIOORG | 1'942 a | 103 | - | - | 1'739 b | 117 | 3'303 a | 191 | 6'984 b | 239 |
CON | 1'614 a | 43 | - | - | 1'993 a | 108 | 3'273 a | 175 | 6'880 b | 119 |
CONBtC* | 1'834 (a) | 179 | 1'573 | 169 | 1'997 a | 161 | 3'481 a | 182 | 8'885 a | 390 |
Average (2007–2010) | ||||||||||
BIODYN | 1'971 | 64 | - | - | 1'603 | 104 | 3'167 | 132 | 6'741 | 270 |
BIOORG | 2'007 | 56 | - | - | 1'638 | 114 | 3'067 | 125 | 6'712 | 257 |
CON | 2'157 | 157 | - | - | 1'738 | 113 | 3'767 | 187 | 7'662 | 455 |
CONBtC | 2'484 | 207 | (787) | - | 1'735 | 140 | 3'605 | 161 | 8'610 | 376 |
ANOVAs of linear mixed effect models | ||||||||||
Source of variation | P value | Df | - | - | P value | Df | P value | Df | P value | Df |
System (S) | <0.001 | 3 | - | - | 0.102 | 3 | <0.001 | 3 | <0.001 | 3 |
Cycle (C) | <0.001 | 1 | - | - | 0.066 | 1 | 0.686 | 1 | 0.912 | 1 |
Strip | 0.141 | 1 | - | - | 0.472 | 1 | 0.960 | 1 | 0.002 | 1 |
S×C | <0.001 | 3 | - | - | 0.039 | 3 | <0.001 | 3 | <0.001 | 3 |
SEM: standard error of the mean, BIODYN: biodynamic, BIOORG: organic, CON: conventional, CONBtC: conventional with Bt cotton, different superscript letters indicate significant difference between farming systems within one Cycle (Tukey test, P<0.05), * in 2009 and 2010 Bt cotton was uprooted 2 months earlier to grow a second wheat crop (wheat 2) to reflect common practice of local Bt cotton farmers (for the sequence of crops in different farming systems see Figure 2), P value and degrees of freedom (Df) of fixed effects in linear mixed effect models, random factors in the model: Year (n = 4), Block (n = 4), Pair (n = 16), for total productivity random factor Year was excluded as data from two years were compiled.