Modern rice farming uses pesticides heavily. Thus, the traditional practice of rice-cum-fish farming was eliminated. However, studies conducted on the use of carbofuran at concentrations of 0.02–0.1 ppm showed that there was no adverse effect on fish and no residual effects on the soil and water (Estores, et al, 1980).
Demonstration of fish culture in rotation with rice using the same paddy showed almost identical cost-benefit ratios of 1.74 for rice and 1.73 for fish. The value of returns from rice is a little higher than fish under normal conditions when rice harvest is good. However, during monsoon season when typhoons often occur, the cost and return analysis could easily shift to fish. More expenses are incurred for rice cultivation than fish culture. This indicates that the farmer has the option to go into either rice or fish depending on his feel of the weather conditions and preference (de la Cruz, 1980).
In the Philippines where land holdings are small, integrated fish-crop-livestock farming would make maximum utilization of resources and increase farm income.
A one-ha integrated farm showed income levels from 
10 000 to 25 000 a year. Such a farm consisted of 1 000 m2 pond for tilapia breeding and 8 000 m2 for rice-cum-fish production. Demonstration work patterned after this farm showed a net income of 8 412.14 in 9 months of operation. A total of 14 crops were grown on the slopes of paddy dikes or along pond dikes. The summary of costs and returns of this farming system is in Table 9,
Further refinements of integrated farming systems are under experimentation in the Central Luzon State University at Muñoz, Nueva Ecija, Philippines funded under the ICLARM aquaculture programme.
Table 9. Costs and income from agriculture-aquaculture farming operations1
| Item | Amount (Pesos) | ||
| A. | Gross income | ||
| Rice | 4 506.89 | ||
| Taro (gabi) | 3 125.45 | ||
| Onion | 3 125.45 | ||
| Tilapia zilii | 1 121.00 | ||
| Eggplant | 518.70 | ||
| Tomato | 329.90 | ||
| Bitter melon | 94.45 | ||
| Pechay | 71.75 | ||
| String beans | 66.00 | ||
| Squash | 58.30 | ||
| Okra | 38.50 | ||
| Sponge gourd (patola) | 36.00 | ||
| Corn | 19.20 | ||
| Sweet potato | 24.85 | ||
| Total | 13 356.39 | ||
| B. | Operating costs | ||
| Hired labour | 593.50 | ||
| Animals/machine | 1 319.30 | ||
| Supplies and materials | 1 766.45 | ||
| Rent: Farm | 825.00 | ||
| Thresher | 440.00 | ||
| Total | 4 944.25 | ||
| C. | Net income | 8 412.14 | |
