Table 4. Mean gross margins [INR ha−1] of cotton, soybean and wheat, and total gross margin per cycle and across four years (2007–2010) in the farming systems compared in central India.
| Farming system | Crop | Total gross margin 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 | 38'243 c | 2'226 | - | - | 19'211 | 4'210 | 26'044 c | 1'584 | 83'498 b | 8'021 |
| BIOORG | 38'676 c | 1'203 | - | - | 21'830 | 4'858 | 24'420 c | 1'291 | 84'926 b | 8'268 |
| CON | 51'792 b | 2'779 | - | - | 18'401 | 4'093 | 37'099 a | 2'221 | 107'292 a | 4'546 |
| CONBtC | 60'811 a | 4'851 | - | - | 18'147 | 4'719 | 31'361 b | 2'832 | 110'319 a | 8'308 |
| Cycle 2 (2009–2010) | ||||||||||
| BIODYN | 62'786 a | 7'217 | - | - | 32'176 | 1'683 | 30'764 a | 2'374 | 125'726 a | 6'721 |
| BIOORG | 64'490 a | 6'714 | - | - | 30'812 | 2'278 | 30'443 a | 2'181 | 125'745 a | 9'354 |
| CON | 42'962 b | 4'653 | - | - | 28'949 | 3'724 | 24'773 b | 2'028 | 96'683 b | 6'701 |
| CONBtC* | 43'810 (b) | 2'995 | 4'837 | 2'190 | 29'399 | 4'644 | 27'037 b | 2'117 | 105'082 b | 5'232 |
| Average (2007–2010) | ||||||||||
| BIODYN | 50'514 | 4’918 | - | - | 25'694 ab | 2’758 | 28'404 | 1’507 | 104'612 | 7'461 |
| BIOORG | 51'583 | 4’789 | - | - | 26'321 a | 2’865 | 27'432 | 1’450 | 105'335 | 7'008 |
| CON | 47'377 | 2’852 | - | - | 23'675 b | 2’780 | 30'936 | 2’155 | 101'988 | 3'089 |
| CONBtC | 52'310 | 3’165 | (2'418) | - | 23'773 b | 3’311 | 29'199 | 1’797 | 107'701 | 3'849 |
| ANOVAs of linear mixed effect models | ||||||||||
| Source of variation | P value | Df | - | - | P value | Df | P value | Df | P value | Df |
| System (S) | 0.115 | 3 | - | - | 0.006 | 3 | 0.022 | 3 | 0.298 | 3 |
| Cycle (C) | 0.046 | 1 | - | - | 0.158 | 1 | 0.606 | 1 | <0.001 | 1 |
| Strip | 0.001 | 1 | - | - | 0.469 | 1 | 0.805 | 1 | <0.001 | 1 |
| S×C | <0.001 | 3 | - | - | 0.150 | 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 gross margin random factor Year was excluded as data from two years were compiled.