An agro-ecological assessment of grower practices in California

264 JULIE GUTHMANchickens are effectively used for both weed control andfield clean up, this sort of control is employed only onvery unusual diversified farms.It is worth mentioning here that frustration withthe lack of technologies for weed control is the mostcommonly stated impediment to expanding organicproduction, although it is more accurately framed asa cost issue. After all, hand weeding and hoeing areeffective technologies, albeit extremely labor intensiveones. In any case, many mixed growers claim that therest of their operations are “virtually organic” exceptthat they use herbicides like Round-up R for spot orpre-emergent weed control.5. Bio-diversified cropping patternsWith the proliferation of inorganic fertilizers sinceWorld War II, the general trend in US farming hasbeen to minimize rotations of fertility enhancing crops(Altieri, 1995). Although rooted in economic structures(e.g., land values, commodity subsidies), this sortof technological innovation has furthered tendenciestoward mono-cropping, which from an agro-ecologicalstandpoint, exacerbates all kinds of non-fertility problems,such as disease, weediness, insects pests, and soforth. It has also enabled an unprecedented degree ofintensification, as evidenced by growers in the coastalareas who can get up to five cash crops per year on anyone piece of land, if the crop mix is right.Cover cropping and non-crop plantings havealready been discussed, both of which happen toincrease farm diversity, but are generally used morenarrowly as fertility management and pest controltechniques. The focus here is on farm diversity morebroadly as an indication of intensive management andecosystem-oriented cropping systems. 10 To increasediversity within agricultural systems, agro-ecologyrecommends that farmers plant and rotate crops ina mosaic pattern of small blocks, and incorporatenon-crop plants into the agro-ecosystem.There is tremendous variation among organicgrowers in regards to diversity, which is primarilyregional and crop specific, although there are clearconnections with scale and ideological predispositionsas well. In annual systems, the minimum practice isthat of temporal crop rotations, where the same cropis never planted on the same piece of land twice in arow. The median is the practice of spatial and temporalrotations, that is, planting different crops, presumablywith very different strengths and susceptibilities,in small adjacent blocks, although block sizes canbe highly variable. This sort of practice is obviouslynot practical with grain crops that are mechanicallyharvested. The maximum are poly-cultural practices,such as inter-cropping vegetables between fruit trees,mixing two or three crops in any given block, andintroducing livestock into the cropping system. In perennialsystems, options are more limited, with theminimum being cover cropping, the median being varietaldiversity, and the maximum, again being some sortof poly-culture, such as inter-cropping with annuals orlivestock integration.Almost all growers do some crop rotations, eventhose in the largest scale mixed categories, and evenon their conventional acreage, although they may notnecessarily rotate in a fertility-enhancing crop. Thepattern observed in this study is that for produce crops,only strawberries, sweet potatoes, tomatoes, and carrotsare grown back-to-back in conventional systems,all of which are once a year crops. Although growersrecognize the potential for more difficult-to-containpest problems, especially nematodes, this pattern isoften replicated when they move into organic production.Small scale growers of specialty crops such asheirloom tomatoes also face the same problem, but aremore inclined to do intensive soil improvement duringthe off season.There is more significant variability in the degree ofspatial diversity on any given parcel. At one extreme,some growers will plant quarter-section blocks (160acres) in one organic crop, usually carrots or processingtomatoes, which have well-developed markets.Other large scale, and mixed operators, plant in 20 to40 acre blocks, which viewed from the ground, hardlyseems diversified. What drives this sort of system isless a commitment to diversity, and more the fact thatthey may have only 80 to 160 acres in organic productionaltogether. Recognizing the need to do temporalrotations, these growers have to spatially diversify tomeet their marketing obligations.When it exists, the sort of small block diversityof several species is found only on small to mid-sizefarms,andisasmuchguidedbymarketingstrategyasanything else. That is, those who do direct marketing,especially through subscription boxes and farmers’markets generally desire as diverse a crop mix as possibleto smooth out the timing of when crops becomeready and to have an array of choices for the buyer. Soeven direct market fruit growers will diversify varietalsso they come ripe at different stages.Farms that incorporate near-ideal poly-cultures,however, are few and far between. I witnessed perennial/annualinter-cropping on only four farms, three ofwhich are owned by long time activists in sustainableagriculture. All are subscription farms, where membercustomerssign-up in advance and receive a weeklybox of various commodities, and all have sales in themedium range. These farms and only a handful of othershave livestock on the farm, but the others tend tobe more segregated, where there may be a horse corral